Any advice on actually finding the idea that is worth doing? I have a notion page with 20+ tiny ideas, but I still don't find any of them encouraging enough to spend time on. How to overcome this very first step?
1. Don't wait for the right idea. Just build a less than ideal idea and iterate. More than likely you will gain insight that leads to a better idea along the way.
2. Copy somebody else's idea. Nobody executes perfectly, and no two founders will execute the same way. There is always room for competition.
Point being, you might just keep building and dabbling and score a winner now and then.
The projects that work are the ones that solve people's problems. The ones that fail are the ones that try to create solutions for problems people do not have.
As an exercise, you could try doing a rough design of a working system to get a feel for how much work it would be. On top of that, you could try imagining all the things that could go wrong and try to predict the likelihood of each. That's what I would do, anyway.
I haven't tested this yet, because I haven't shipped my 90%-complete project from 2 years ago yet…