I generally play with golds and silvers (yay low elo), and can say that it isn't too different from my experience. But I'm not anything special, so take anything I say with a grain of salt.
But the differences that happen in what I see, are that CS becomes very important, more so than kills. Kills, if you can get them, it's fine -- but don't lose out on CS. Also, if you're that far ahead, you need to be helping your team get fed. If it means purposely giving them kills or letting them KS you, you do it. If it means making a shot call on taking turrets over helping the teamfight, you do it and vice versa. Judgment. This isn't 1v5 game. People do get outplayed or just lose lane, someone has to. If you're complaining about your team, then it will always mean that a part of their loss is your fault. Regardless of if you complain or not, the loss will always have a percentage of blame on you, as for everybody else. And it's not a bad thing because if you sit and analyze yourself after each one, you will always learn something you could have done to have made it better.
Riven excels in teamfights, so you should be putting your teams positioning and yourself in a smart way so as to eliminate targets in order of their threat level. Zed does the same but requires very high skill to pull off and take out priority targets in the middle of the enemy team while still being safe. Combine that with all of the above, and it's a start. These are just words, I can't make you listen nor can I prove them to you myself. You just should consider them and decide for yourself if it seems like it's reasonable.
