Hi Meredith. Place your right arm between the ears with your hand on the forehead. Put the bridle in your hand and let it dangle. Give a treat. Once you've mastered this, proceed with placing the bit in her mouth and raising it with your fingers of the right hand. One ear forward, then the other. Good luck!
If she's just doing it to make life difficult, then start loving and hanging on her head on the ground all the time. There's a little "button" on the top of their head right on their poll behind the ears. Push and she should give you her head, when she does it love on her to show her that she did what you asked.
It's worked for all the headshy horses I've been around.
Unfortunately I've been loving all over this mare for the last few years but she just snaps when I try to bridle her. The bit is no problem, she accepts it willingly, but as soon as I bring the bridle near her face she loses it. I've started using an English bridle with the browband removed and I've been doing it up like a halter and it seems to work for her. She is fine in the round pen, but in the barn or by the tie post she can't handle it. It's very bizarre.
Don't approach too slow or your horse will think you're sneaking him, he would consider this as a threat. The better way is to reach to his head gently, softly but not tout slowly, show confidence and natural. When he starts to relax and stops moving away give him a release by removing your hand and leave him alone.
Take it really slow. Start by loving on their neck and head/ears with the bridle over your arm. Slowly, only when their calm, start rubbing the bridle over their neck and head. When they are okay with that slowley go to bridle.
Give that a try and after a couple times they should get better. You have to make them like it and learn nothing bad will happen when they go to get bridled. Also lots of love and encouragement helps a bunch. Going slow is the most important thing