'focuses more on increasing your passive income while maintaining a job and living a healthier lifestyle'
Agreed. This has been my philosophy, and it has worked out well. I start in an area where I want to learn the skills required to create the product, allowing for a good ROI even if no revenue is achieved. I also require that it can scale without more work on my part. I end up with something mostly fun to build, more resume items, and possibly a decent passive income. Since I do have a career separate from the projects, I do not have a lot of pressure to stress myself to death in order to make it my sole income.
The hardest part is marketing. So, I try to start something where I have a reasonable 'in' right off the bat and try to grow organically. Every once in a while I will start a search ad campaign or find a place for a banner ad. The best success I have had so far is by banner ads and word of mouth. I only need a small piece of the pie!