At the highest level, the trick is to actively do things to increase momentum while avoiding things that reduce momentum. Pick a stack you know, build a way to collect money, release before you've even written code, etc.
I wrote a post titled Side Projects: Avoiding Failures to Launch[1] a few months ago that touches on these same ideas in more detail.
I wrote a post titled Side Projects: Avoiding Failures to Launch[1] a few months ago that touches on these same ideas in more detail.
1: https://blog.benroux.me/avoiding-failures-to-launch/