Remember - Pay attention and think during champ select.
Recently got out of a game.
Us: Corki, Janna, Diana, Zed, Yasuo. Them: Ezreal, Soraka, Kayn, Kat, Tryndamere.
So obviously neither of us had a tank. But you see, in champ select we could have avoided that. First of all, Diana bans Alistar on accident even though our support wanted it. Yasuo and Zed both instalocked - fine. Too much AD. So I say I'm going Corki. Our jg is like "no I'll go AP." To which I said, "No - corki is mostly AP, go a tank. You already banned out our tank so please. We need a tank." She instalocks Diana.
Now, of course, she gets super fed because both teams are squish and Diana is pretty much point-click-die. But we lost. Our Diana had a score like 21/4 and we still lost. Because we couldn't stop Tryndamere as we had minimal cc to do so.
The moral: yes sometimes you can bank off of "getting fed." But even then, sometimes you have to take one for the team (Especially when you screwed someone over in champ select)