Play Pantheon, GGWP! Joke. I'm not a high ELO player but I noticed that I'm climbing a lot since I started having more awareness in the minimap. People really undervalue its power. Even people that ward a lot don't benefit as much as people that check the minimap from every 5 seconds. Decision making i think it's very important to understand what objectives you should go after. You ace the enemy team, what you do? You should try to get something from it, obviously, like a turret, inib, or a drake/baron or even just pushing waves. You have to punish the enemy team from losing the teamfight, so don't back without profit from it. Also don't be greedy. You get an inib, don't push further to get a turret, you might lose the game from those risky plays. Reset, go back, buy stuff, get buffs and focus on pushing other lane, get more turrets, or force a teamfight if you are sure to win. These are just some tips. One interesting tip about warding is to ward the baron exactly behind him, some people have a bad time trying to destroy the ward but they just hit the baron instead.