What age and what style of flag football?

I coach 5 on 5, flag football where you can rush the QB as long as you line-up 7 yards beyond the LOS.

Depending on the defense, I try to use a progression of plays to make the defense cheat and get caught out of position.

Lots of reverses, fake sweep end arounds, and fake reverses. When the defense starts to "stay home" to defend the reverse, we'll line up trips and from in to out have the WR's run a screen, stop, and post, and let the QB which ever man isn't covered.

If the defense does shift to cover the trips, I like to have the QB roll out to the strong side and then pass to the center running a short route on the weak side. Younger players have a hard time watching the entire play, so we will also line up trips right and have the QB drop back to pass. All they see is pass, so a Statue of Liberty play will work great. It only works once a game, but the next time you go trips at least one player will be looking to defend the statue and you will have an open receiver.

I am far from a pro, but I have some 5 on 5 play sheets that I created. I can email them to you if you are interested.

Look here:
http://www.y-coach.com/forums/index.php?showforum=23
Lots of free playbooks for both offense and defense.