Develop to landing page
I've gotten very good at talking myself out of doing any side projects. Finding flaws and planning for failure, the qualities that help me a lot at work, don't let me believe in my ideas enough that I would take them to life.
On the other end of the spectrum is the hopeful entrepreneur making a classic mistake, developing a product before confirming she has a verifiable edge over the competition, and solves a problem real people have. Edward Thorpe said it the best in “A Man For All Markets”: in business, just like in gambling, you only play when you know that you'll win.
I decided that for some current ideas, as well as new ones that I consider viable, I'll withhold judgement. Instead of gauging whether the product would work, I'll take it unconditionally to the landing page stage. It takes almost no commitment and creates no technical debt, it's just a domain and some static HTML. It's a win-win from any point of view: I spend much less time on it than building the simplest MVP, writing a description forces to be precise about the idea and its details, and I can show the result to people, perhaps potential users.
You don't even need a landing page. Market research should come first in talking to your future users. But my ideas usually have me as the user, so I can make the first pass without talking to people.
I'm working on a project right now, and I'll add a link to it to the Projects section soon.