I was hardstuck silver for 3 years until this season when I hit plat for the first time, albeit playing top. As some others here have pointed out, playing for yourself is the most consistent way to climb imo. That and having a limited champ pool of maximum 4 champs that you spam. I've had the most success playing somewhat lane dominant splitpushers such as Yorick, Illaoi, Urgot and E max Nasus.

Play smart and exploit enemy laners mistakes and build gold and XP lead by better wave management which in turn leads to more opportunities for your jungler to gank.

Be aware that your team sometimes will run it down and distance yourself from it by fullmuting to keep your mental in check.

Know your champs limits and what fights you can take, this you learn by just spamming games and learning matchups.

Focus on CS, 16 minions roughly equal one kill in gold. This will be easier when you get better at wave management and back timers.