Haflinger has the right idea. In general, collection comes last, and take it slow. Some trainers may find a "quick fix" such as draw reins or even a harsher bit, but in the end you'll have a better trained horse and much nicer ride if you take it slow and work on the basics. A forced horse is never a pretty picture, even if you have its head in the right place.
Jazz and I worked under several different trainers, all of whom had different solutions to his hard yet rather finicky mouth. They tried all kinds of bits and contraptions, including curbs, draw reins, harsh twists, german martingales etc. Though there is a time and a place for some of them, most of it is just a temporary solution. He'd be good for a while, and then go back to either bracing himself against the bit or throwing his nose up in the air, depending on the equipment, tactic and mood he was in. He didn't like shows to begin with, so we gave up and took him to a small boarding stable, and pretty much retired him for a while, and I moved on to own and show other horses. I had my show horses in training with a trainer about 6 hours away, and kept Jazz in town to stay practiced riding. Once I became sensible and just put him in the smooth snaffle and worked together with him, we began to make progress. It's taken years to get him where he is now, but anymore I get on his back, check him back a little while applying leg and seat, give as he gives, and he's in frame and ready to go. Today I got on him bareback when he hadn't been ridden for quite some time, and there he was collected up and moving along.
Take your time, be patient, be soft, and remember to give back. You'll never win tug-of-war, so you have to convince the horse that her life will be easier if she gives to you: give back when she gives!