What are some good Call Of Duty Zombies tactics/plans/cheats?

Me and my friend always like to play zombie mode on Black Ops, our map we always use is Kino Der Toten. By the way, Xbox 360 version. Now almost every time we play we never have a good organized plan or know any cheats to help. Our level record at the moment is 18. We usually either just run-and-gun doing laps around the map and hopefully don't get hoarded, or just yell at each other on what to do while zombies are surrounding us. Yeah, not very good...But we're just playing for the fun of it, not to be a hardcore player/hacker. So anyone have any suggestions,plans,tactics, or maybe even cheat codes to make our game more enjoyable??? :)