Consistency, I'm afraid.
You always start with a whisper-light pressure and then increase until you get the desired result (a shift of weight will be the first result.)
Once you get that shift, release all pressure and praise. Repeat again until you get that shift again, then release.
Keep doing this until she shifts right away. Then wait some more and she'll think "hmm... pressure didn't go away.. either my human is silly and forgot to release or I need to do something else" so a try will happen. She might push into you, keep the pressure consistent, don't add or decrease. "Nope... that's not what she wants" then she'll try to move away from the pressure and as soon as she does, you release. "Okay.. I wonder what that was about" repeat until the message is clear "pressure applied to my side means I need to move away from it"
OP it's easiest to start with a yield of the haunches and forehand before you go for the full whammy of side pass.
When you can do both really well on the ground, in saddle she should pick it up rather well.
It's going to be a little daunting for both horse and yourself since it's about clear messages and truck load of patience is needed. Be sure to switch sides and get her doing each step on both sides.
1. Shift of weight to pressure
2. Move away from pressure
3. Continue to move away from pressure
4. Yielding of _________ (hind, shoulder, barrel, head, etc.)
"Strength is the ability to use a muscle without tension"
Last edited by Skyseternalangel; 05-16-2012 at 08:50 PM.