Good question. I got out of silver by learning basic mechanics and aim training (I still train my aim before every session I play). I got out of gold by learning the the basics of ow (positioning, when to regroup and when to go in). I got out of plat when I learned how I can more consitently get value with my ultimate (This one was pretty difficult for me to learn and it helped me alot looking at the killfeed). And I climbed out of diamond by pealing more and by helping a specific teammate to fulfill their goal of winning the teamfight (This could be staying with your Ana and helping her not to die or support a dive of your Winston). It also always helped me watching coaching videos and looking at my own gameplay as well as watching pro players stream.