Master Reading Your Mini Map
I firmly believe the biggest reason why I'm good at video games in general is because of the existence of the mini map. As soon as you can start to read and analyze situations by looking at it, that's when you're really going to be able to push your game to the next level. Look at it as often as possible because it can tell you so, so much, like where enemy minions are and where enemy heroes are, and in turn you can use that information to analyze whether or not you can do certain things like engaging the enemy, go hunting for buildables or get the neutral thrall camp. If your team isn't very talkative, your mini map is going to be the best way of figuring out the flow of the game.