im not diamond but i got to plat 5 like hour ago
the best thing for me is to check how i feel, if i feel tired i play a little worse than i should, spacing my games and making sure that i feel good and ate enough sugar helps me (sugar is good at fueling the brain, opening your window would also help)
allowed me to get an insane win spree on ranked, also normal games, with the current matchmaking it wont dull your skill while it might remove most of the frustration you get from losing
also i would like to add a question of mine, the topics are similar, is it like a big gap beetwen plat and diamond? i would like to get diamond before season ends for the preetiest border, and i was silver 1 last season (neede 5 lp for the promo to gold and elise skin but for some reason my team trolled while enemy team went straight for the win, so you know... i cry everytim)
normaly i would assume that its just polishing whatever i learned during the climb from bronze that i started in s3 but you never know if you didnt get through it.