How do I become a diamond player in League of Legends?

Easiest way to do it is play at least 2000 games a season, at minimum. The other thing you’d want to do is watch pro’s and streamers who are at that level, understand their micro/macro. Find a champion you want to play, and play that specific champion for the majority of the ranked games you play. If you are able to learn from your mistakes, it should be doable in a season provided you put in the time and effort.

Thanx a lot for your reply. Recently I`ve gone through League of Legends coaching and should say it worked pretty well for me. I got the best gaming experience and got a new level. I simply focused on specific champion and got help of PROs. They worth every penny spend.