How to build a successful side hustle, despite past failures

The Graveyard of Failed Ventures

I’ve failed at every “side hustle” I’ve ever tried. Let me walk you through the wreckage:

T-shirt designs: I spent weeks weeks learning design software, creating what I thought were clever shirts, and setting up a print-on-demand store. Total sales: zero.

Online course: Built a comprehensive resume-writing masterclass on Udemy. Recorded hours of video, created worksheets, designed the curriculum. A handfull of students enrolled. When the course was no longer free, people stopped enrolling.

Music production: Wrote and produced electronic tracks, distributed them through DistroKid under artist names I thought were creative. Negligible streams: negligible, literally pennies in revenue.

Resume writing service: Figured I could help people with resumes since I’d struggled with my own. Set up a website, advertised locally and online with flyers and business cards. Clients: 2.

Deer aging website: Built a computer vision tool that estimates deer age from photos. Hunters actually found this useful and I got a little traffice. No sales conversions.

Tutoring service: Offered physics and math tutoring online and in-person. Surely students would pay for help from someone with a PhD! Students who signed up: zero.

Eyewear invention: This one hurts the most. I invented, developed, and produced an entirely new type of eyeglasses. I spent years on it, honing the final product. The product exists, works great, and I have videos from friends trying out my prototypes. Market traction: none.

Each failure cost me time, money, and emotional energy. Each failed path felt like more evidence that I just wasn’t cut out for entrepreneurship.

Then I stopped trying to be an entrepreneur, and everything changed.

The Mistake I Kept Making

Looking back, every single failed venture had the same fundamental problem: I was trying to build products in markets I didn’t understand, for customers I’d never met, using skills I hadn’t proven.

I designed t-shirts, but I’m not a designer and I don’t understand fashion.

I made music, but I’m not a musician and I don’t understand what makes songs resonate with listeners.

I built a deer aging tool, but I’m not a hunter and I don’t understand what would make hunters actually pay for a tool like that.

I was essentially walking into crowded arenas, competing against people who had spent years mastering their craft, and expecting to win because I was smart and worked hard.

But that’s not how markets work.

The Realization That Changed Everything

Here’s what finally clicked: I already had valuable skills. I just wasn’t selling them.

As I mentioned in my introduction, my career has been unconventional, but I’d accumulated genuine expertise along the way:

Years of experience with data analysis and signal processing
Published peer-reviewed research in optical physics and satellite communications
Hands-on work with machine learning and computer vision
A PhD that, while I’d never “used” it directly, had trained me to learn complex topics quickly and work independently (more on that later).

None of my side hustles leveraged any of this. I was trying to become a t-shirt designer when I was already a data scientist.

Everything shifted the moment I asked “who would pay for what I already know how to do?” instead of “what product could I build?”

From Products to Services: The Pivot

Instead of building products for hypothetical customers, I started looking for companies that needed skills I already had.

The logic was simple:

Products require you to understand a market, build something people want, market it effectively, handle customer service, and compete with established players — all skills I’d proven I didn’t have.
Services require you to do work you’re already good at, for clients who’ve already identified their need, at rates set by market demand for that expertise.

I didn’t need to become an entrepreneur. I needed to become a consultant.

Where I Looked

I started with two platforms:

Kolabtree: A freelance platform specifically for scientists and researchers. Companies post projects needing PhD-level expertise, and qualified experts bid on them. The projects range from literature reviews to data analysis to experimental design.

LinkedIn: Not for job searching, but for visibility. I updated my profile to emphasize the specific technical skills I could offer, and I started engaging with content in my field. I also started networking and looking for part-time hiring opportunities.

I also did something uncomfortable: I told people what I was looking for. I mentioned to former colleagues and professional contacts that I was available for consulting work in data analysis and machine learning. Word of mouth turned out to be powerful.

The Pitch That Worked

On Kolabtree, I bid on projects where I had direct, demonstrable experience. For evidence, I pointed them to my website so they could see my craftsmanship for themselves. My proposals followed a simple formula:

Acknowledge their specific problem (illustrating I read the posting carefully)
Briefly explain my relevant background (1-2 sentences, focused on exactly what they need)
Describe my approach (shows I understand the work, not just the topic)
Provide a realistic timeline and cost

Here’s a real example of the structure I used (with some details changed):

“Your project involves classifying [X] from image data, and this is directly in my wheelhouse. I developed similar classification models during my work at [Company], where I built computer vision systems for [application]. For your project, I’d approach this by [brief methodology]. I can deliver initial results within [timeframe] for [price], with a full report including methodology documentation.”

The key is specificity. I wasn’t saying “I’m a data scientist who can help with anything.” I was saying “I’ve solved this exact type of problem before, here’s how I’d solve yours. They’re related, which means I already have a jump on finding you a solution.”

Getting Employer Approval

This part worried me, but needs to happen. Would my full-time employer see consulting work as a conflict of interest? A distraction? Competition?

I decided to be completely transparent. I scheduled a meeting with my manager and explained the following:

I wanted to take on limited consulting work (specific hours per week)
The work would be in adjacent areas, not competing with our company’s business
I’d ensure it never interfered with my primary job responsibilities
I wanted their explicit approval before proceeding

I also gave them a full write-up of the work my side gig would entail. This allowed them to see for themselves that there was no conflict of interest.

The response surprised me: they were supportive. As long as the work didn’t compete with the company and didn’t affect my performance, they had no objection. It turns out several of my colleagues had similar arrangements (including my manager)!

If you’re considering this path: Carefully check your employment contract for any consulting or moonlighting restrictions. When in doubt, explicitly ask and get approval in writing. The transparency protects everyone.

The Results

Within a month of shifting my approach, I had secured two part-time consulting roles.

The work was immediately engaging because it matched my actual skills. I wasn’t struggling to learn a new domain, I was applying expertise I’d built over years.

The income was meaningful. Both roles combined bring in over $30,000 per year, with potential to grow as I build relationships and reputation.

Believe it or not, the financial benefit wasn’t even the biggest win.

The Compound Effects

Each consulting project created additional value:

Expanded expertise: Every project exposed me to new problems, new industries, new approaches. I was getting paid to learn.

Portfolio growth: Completed projects (with client permission) became case studies I could add to my professional website. This is the same website strategy I discuss in my post about landing job interviews — the consulting work gave me more material to showcase to future recruiters and hiring managers.

Network expansion: By necessity, each new client introduced me to their network. People who need consultants often know other people who already use consultants.

Resume reinforcement: The consulting work provided social proof that my skills had market value beyond my primary employer. This is valuable leverage in salary negotiations and job searches.

Risk reduction: Having income from multiple sources means losing any single source is less catastrophic. Financial diversification was my original, and I actually achieved it, just not the way I originally imagined.

Why My Failed Side Hustles Actually Failed

With hindsight, I can diagnose each failure more precisely:

T-shirts, music, resume service: I had no credibility, no audience, and no differentiation. I was a random person competing against professionals in their own domain.

Online course: I had some credibility (I had written resumes), but I didn’t understand the Udemy marketplace, how to drive traffic, or what students actually wanted to learn.

Deer aging website: This one’s interesting because the product actually works and provides value. The failure is monetization — I built a ‘free’ tool that requires users to pay for continued use. The traffic proves people want it, I just haven’t figured out what they’d pay for (this remains an active puzzle I’m working on).

Eyewear invention: Classic inventor’s trap. I built something innovative without validating market demand, underestimated the difficulty of manufacturing and distribution, and ran out of runway before gaining traction.

In every case, I was trying to build something new in a space where I had no existing advantage. Consulting flipped this: I was selling something I’d already built (my expertise) to people actively looking for it.

How to Apply This to Your Situation

If you’ve been struggling with side hustles like I was, here’s a framework you could implement:

Step 1: Inventory Your Professional Skills

Write down everything you do in your job (or have done in past jobs) that requires specialized knowledge or training. Include:

Technical skills (software, tools, methodologies)
Domain expertise (industries you understand deeply)
Credentials (degrees, certifications, clearances)
Rare combinations (you might not be the best at X or Y, but “X + Y” together might be unusual)

Step 2: Identify People Who Pay for These Skills

For each skill, ask:

What types of companies use this skill?
Do they typically have this expertise in-house, or do they hire it out?
Are there platforms where people look for this expertise?

Google searches like “[your skill] freelance” or “[your skill] consultant” can reveal marketplaces and rate expectations.

Step 3: Package Yourself Appropriately

You’re not looking for a job — you’re offering a service and build a brand. This means:

Describing what you do in terms of outcomes, not just capabilities
Having examples of past work (even if from your regular job, with appropriate discretion)
Being able to quote a rate or project price
Having a way for people to find you (LinkedIn profile, personal website, platform profiles)

Step 4: Start Small and Specific

Don’t try to be a general consultant. Pick one specific skill and one specific type of client. Make your first pitch as narrow as possible.

“I help e-commerce companies analyze customer behavior data” is better than “I’m a data scientist.”

“I review mechanical designs for manufacturability” is better than “I’m an engineer.”

Specificity builds credibility. You can always expand later.

Step 5: Tell People

This is the hardest part for most people (including me). But consulting opportunities often come through word of mouth. You have to let your network know you’re available.

You don’t need to be salesy. A simple “I’m taking on some consulting projects in [specific area]. If you hear of anyone looking for help with [specific problem], I’d appreciate a referral” is enough.

The Mindset Shift

The biggest change wasn’t tactical, it was psychological.

I used to think side hustles meant building something new, being entrepreneurial, and creating a product that could scale. That framework made me feel like a failure every time something didn’t work.

Now I think about it differently: a side hustle is any way you convert your time into money outside your primary job. Products are one option. Services are another. And for people like me — people with specialized professional skills but no particular gift for entrepreneurship — services are the far easier path.

I’m not saying product-based side hustles are wrong. For some people, they’re the right fit. But if you’ve tried the Etsy shops, the online courses, the print-on-demand stores, the apps, and none of them have worked, you may be like me. Maybe you’re already sitting on something valuable and you just need to sell it differently.

Stop trying to build something new. Start selling what you’ve already built.

Next up: How to land job interviews, despite failed applications

Previously: How to land your dream job, despite improper planning