Stick to hobbies or interests. Be an expert (even if you aren't one) on something. I worked as a stereo installer and salesman for over a decade before I quit my job and started learning IM. One of the first things that I did was to start selling some of the parts and cables that I accumulated over the years on eBay. This was an excellent source of income and the next step for me was to create a website that had these items available for sale.
I knew nothing about web design and figured I would need years of experience with CSS and coding or use expensive website building programs like Dreamweaver or something like that. Then, in my research, I learned about Wordpress web design and affiliate marketing. I started with Amazon and built a few websites in the car stereo and GPS navigation niche. I built review sites about speakers, amplifiers, and in-dash headunits. I turned my passion for car audio and previous sales/installation knowledge into a passive income stream.
Sometimes, the idea for a new website or internet marketing project is right in front of your face. I always recommend that people start with their passions or past experiences. If you have knowledge and background dealing with a subject or niche, use it to make money. If it interests you, then you will never run out of creative juice.
