For the PA28, I agree with Charlie Foxtrot India.
But in the Bulldog (which had rather more power), we always left the flaps as they were until airborne at a safe height.
Whatever - DON'T fiddle with the trimmer on the ground during a touch-and-go, particularly if it's one of those Austin 7 window winders dangling from the ceiling in an early PA28! Because the body movement can induce a rudder PIO and off the side of the runway you go!