Are you allowed to blitz on Defense?
My favorite defense to run in intramural flag football was to have the corners play man to man on the outside recievers. 1 safety deep, 3 guys playing underneath zone and one guy rushing.
It would usually take until the second half before they figured it out!
Also on offense, can the QB run? If so just put your most athletic person back there.
Good play for offense is 4 wide, 2 on each side, outside guys run ins, inside guys run outs....similar to a pick play. Once you burn them a couple times with a 10-15 yard out you switch it up, call the out and UP, shimmy a little pump fake to get the corner, then work on your touchdown dance