I use a prolite headpiece, I have done for about 2 years now. I call it my poor man's elevator bridle! To be honest I don't know if it makes a mega difference but I feel happier that it is on. The main thing is to ensure that your browband is big enough as the headpiece can make the browband tighter.
I used one on the underside (buckle) of my horses noseband as it used to rub her. It worked really well but then I lost it and bought a KB bridle instead which is padded anyway.