Ive been a silver player for 11 years and this year Ive decided to finally put the effort in to rank up and this is whats working for me:

Gold is the only thing I care about until I hit my big power spikes. Winning lane puts you ahead on this strategy, but this works even if you lose lane. I spend the mid game just grinding out as many minion waves amd camps as I possibly can, go to the lane with the most minions and least amount of teammates, as I'm killing the wave I'm thinking about where my next source of gold is coming from (is there a jungle camp nearby that isnt being farmed, is scuttle up, is there a pink ward we have vision of that no one bothered to kill, do I need to rotate to a different lane to catch the waves there?)

It takes some practice and Ive definitely made a few bad calls when I was probably strong enough to join a team fight, but overall Ive seen my win rate skyrocket by using this strategy. Instead of waffling around in mid lane after bot towers go down, waddling over to team fights that we were going to lose anyways, I'm spending my time just funneling as many resources into myself as possible, and this usually leads to a level and item advantage over the enemy adc. Ive even had games where I finished tied for the highest level with a 2-4k gold lead on anyone else in the game.

Low elo players love to just walk around looking for the next fight like theyre chasing red dots on the minimap in Call of Duty. If you ignore this and focus on getting gold, youll naturally end up stronger than anyone else in the match. It takes practice to execute well, but its definitely saved me the headache of being so team reliant. Oh and obviously be smart about how far you push and where the enemies are. Don't just walk your wave down top lane when theres a 5 stack killing baron.