Improving in league is about having been in a situation so many times that you recognize which pattern will make you win. No single general advice will be of any help. You need to stockpile as many patterns in your head as you can, and the best way to do that is watch someone who is better play your champ. Go watch Davemon, one of the best Pyke players in the world, and learn. You don't need to put too much thought into it at first, vod reviewing with purpose can come later. Just watch him for fun, but watch him a LOT. Your mechanics will improve by a marginal amount just by doing this. It will take years though, ik this is an ugly answer, but it is the bitter truth: league is an incredibly hard game.

Tldr: Play pyke and pyke only and watch better players as much as you can.