Patsy, it depends what your position is in regard to the aircraft you are formating on.
Line abreast or vic should result in very little turbulence at all.(unless you are flying very close, a la red arrows).
Line astern depends on how close to the centre line of the preceeding aircraft you are and the distance from it. Some aircraft are very smooth to fly behind, some quite violent and some have a turbulent area that doesn't disappear until you get within 60 - 100 ft of them. It helps if you avoid flying directly behind the engines or wing tips.