How about MUST READS!
1) Don't use idiotic army comps. Not going to list them all, but I've seen drag+healer, barch, goblins..etc. Use common sense, if you cant afford it, let leaders know.
2) Draw out clan castles with most compositions or you will fail. Drawing out CC isn't hard, and you don't want to get 0 stars because you forgot! (Ex where you don't need: Mass drags attack)
3)Don't TH snipe.
4)ASK FOR HELP. If you don't know how to attack AND you don't attack, you hurt yourself AND the clan's chances at winning. What's the point of a clan if you don't utilize it? Don't realize you need advice the hard way by getting 0 stars first.