PSA: Stop being Greedy.
You invaded 4 v 5 and spent everything to kill the support? Well done, you got first blood. Head out and spend that extra 50 gold. Wait, what? You want to steal their blue 4 v 4 after you blew everything on the enemy support?
Announcer: " Enemy double kill!"
Fuck me. I hate when people don't know when to fold them. One of the biggest reason people ever lose, is because people don't know when to fucking stop being greedy. I've been playing since mid season 1 and I've seen it happen so many times. People just don't know when to back. This leads to enemy champs getting kills or multiple objectives when done so in early to mid game. Not knowing when to back in the late game? GG, you just costed your team the game.
I wish people used their heads a little more and think on how their actions can impact their team as well as affect the enemy team's decision making when they see that you don't know when to back.
tl;dr: Play safe. Even if you have to lose CS in your lane or a buff in the jungle, its so much better that you don't die and give the enemy team a bigger advantage by killing you.