Sabine also needed to learn to lift her feet and have them held for the farrier, and she needed to learn to stand for the farrier. She was "learning to learn" - that's a phenomena where animals (and humans) learn each task faster, because they've learned how learning works. In Sabine's case, she was learning I wasn't going to hurt her. And if she stood still and relaxed, I would stop bugging her more quickly. Because she was learning more quickly, I worked on these two tasks in the same session.
For her feet, I decided to use a philosophy I had learned at a recent clinic. That was that each thing you do with a horse should be "just the next thing". That means that you prepare them with your previous lessons, and then each new lesson is just an extension of the previous ones. It also means that you approach the new lesson with the idea that it is no big thing - you are just doing "the next thing". And your confidence projects to your horse.
This worked well for teaching Sabine to pick up her feet. I had already taught her to let me rub her anywhere. So I started rubbing her neck, then rubbed her shoulder and then her leg. When I got to her pastern, I learned into her a bit, and picked up her foot. The second she took it off the ground, I let go. I worked on both front feet until she was picking them up with minimal pressure. This took a few sessions. But once she got that and was consistently picking up her foot, I moved to the next lesson. I then asked her to hold her foot up for five seconds. In the beginning, she moved around and I just held onto her foot until she stood quietly. Before long, she was holding each front up for 5 seconds. I then increased the length of time by 5 seconds each session until she was holding them up for 30+ seconds and standing still.
Once she knew how to hold up both front feet, I started picking them out and then running my hands all over them, mimicking a rasp, then slapping with them with my hand to mimic a shoe going on, etc. When she was good with the front feet, I repeated the lessons with the back feet.
During the same training sessions with the feet, I worked on fly spray. In the beginning, I used water in a bottle so I wouldn't waste fly spray. I started by spraying it around her, not at her. If she moved off, I stayed with her and kept spraying until she stood still and relaxed. Once she did well with that, I started spraying her - starting at her front legs and shoulder. Again, this took multiple sessions, but once she got it, I started using actual fly spray.
And throughout all these sessions, I reminded Sabine of her lessons in giving to pressure. I asked her to back, lower her head (in response to poll pressure), and flex to the left or right.
I taught her to stand for being hosed off in the same way - hosing slowly, stopping when she relaxed, and keeping with her when she moved around. She accomplished that lesson in just one day.