with 4-5 basic plays that they can master by the 2nd or 3rd practice. 3) Make armbands with the play diagrams that they can wear at games and practices. 4) Lots of square-ins and square-outs at practice. 5) Use a basic Cover 1 defense - best athlete plays safety. 6) Teach backfield contain on defense.
Also plan on having 5+ balls for practice.
And, most importantly make it intense & fun. Flag football can be the most fun they have playing football.