[0wis]

Interested too. I did several full courses and exercises on it (Freecodecamp, W3, Mdn, Codepip…) and I still struggle a lot to create clear UI and have each HTML element where I want them. I am looking at CSS frameworks (BEM, Tailwind) but I would like to master « vanilla » CSS.

[toastal]

It’s not a direct method, but really, you should try a) study the source code of the big ‘frameworks’ such as Bootstrap (especially if you dig into the comments & issues / patches that fixed worse practices with better practices) & b) hit F12 to start inspecting sites that are doing things interesting that you’d like to know about (but keep in mind they might not be experts & how you might improve it).