One of the hardest things for me is (or was) consistent styles, because I'd change something with every new project, and several projects down the line, everything was different.

Somehow I was too hard on myself (or should I say perfectionistic?)

But,... I found a cure :) Developing JavaScript (ES6) means I have access to all sort of tools and one of the best out there is Eslint. On top of that, I use AirBnbs rules and no more issues - all I have to do is take someone else's directions and be happy with them. No more styling OCD :)