The problem of the occasional arrow to the right is usually caused by gripping the bow in expectation of the shot. Relax your bow hand and think about NOT grabbing it. If you have a wrist strap, you know you are doing it right when your bow starts to roll forward after each shot.

I had this same exact problem a few years back and on a recommendation of a friend bought a box of toothpicks for .59. I would place a toothpick between my thumb and pointer finger of the hand holding the bow, and the first time I tried to shoot I almost drove the toothpick through my thumb from trying to grip the bow.

A few dozen toothpicks later I didn' t think about " gripping" my bow anymore.