As a diamond player, I can fully say that if you do the following things you'll get places.
1: Always blame the Jungler
2: It's never your fault.
3: When you lose a 1v1, always try to win it right when you get back to lane. Until you win.
4: Never follow your teammates, and always be on the other side of the map. Especially if you are the support.
5: If you see someone who has a big bounty on them, always try to solo kill them. Don't want to risk giving that gold to another player.
6: Flash is a bad summoner spell to use.
7: Always pick Yasuo, Riven, Zed, Master Yi, and Vayne.
8: Never build defensive items. Don't need them if the enemy is dead.
9: Don't get objectives, that is some weak shit. Only scrubs think about those.
10: Do the opposite of all of that.