My girl, Lacy, does a similar thing. As soon as I get on she starts freaking out (her saddle fits pretty well, too) so I've taken to lunging her every time I go out there to help her get out some of her energy and help her get into "working mode". I only lunge (walk/trot, maybe canter, with lots of transitions and direction changes) for 15-20 minutes so she's not tired or anything she's just in a better mindset for working. It seems to be really helping. She still gets a little excited but it's more controllable since she's already been responding to my directions on the lunge and she's not irritated anymore that I'm interrupting her lazy day. Also, when I lunge her a little it helps me get an idea of how she's feeling that day, for instance if she's listening well on the lunge she'll probably behave well when I get on, and if I should change what I was planning to do that day or whatever.
Then if she gets wild after I get on, I just grab mane with one hand (if she's rearing and bucking) and ask her to do lots of turns and serpentines and figure 8's with my legs since that makes her think more about what I'm asking. I won't ask her to trot until she's responding really well at the walk.
Last edited by Wallaby; 02-09-2009 at 04:27 PM.