1. I've seen alot of fed players who lose late game or they don't even know how to team fight.
2. Fed enemy players tend to leave lane and roam to top/mid/bot.
3. That jungle farm isn't just for the jungler plus most of them tend to ignore wolves or rock monsters later in match so steal them for teh golds.
4. if someone is behind, defend a lane and let that guy/girl farm on overrun lanes.
5. I know its annoying to mute some ragers but just mute them for a while and tell them "Chill out, muting you till you calm down".
(reason why is sometimes good communication helps so this is why im one of those guys who hates to mute a player in game)
6. If jungler gets invaded help him, if jungler gets behind farm by disconnect, lag etc help him/her out with 2 or 3 camps. (supports im looking at you).
7. Supports can can carry you after their booties and sightstones so shad hap you bot lane Rivens... oops i mean Vaynes.
8. Have fun and stop treating moba games like a job. You wanna try having a job in real life and get bossed by some douchey buttload of a superior worker XD its annoying and nobody wants that in a video game which is ment for entertainment.
9. If its normals, dont whine at someone wanting to break meta, your promotion series to cardboard 5 isn't on the line here.
10. People make mistakes and you do to, dont you lie to me saying that you never make mistakes.
11. Git gud.
12. If support has more kills than everyone in your team then you need to git gud.