btw, what can I do when a horse is trying to buck or shake me off? How do I calm it down asap and stay on? Thanks!
To answer tinyliny's question, my foot does come out of the stirrup sometimes but its usually because I don't keep my heels down, and I have weak ankles. So there's not much power when I flex the balls of my feet downwards. But they are getting stronger; riding has helped!
Stop thinking of it as "heels down" or "toes up" - and start thinking of it as Weight In Heels. When you think of it this way, you aren't entised for FORCE your foot into an uncomfortable or unnatural position. Instead, you will start to allow your bodies weight to naturally flow into your heels, without forcing it. It doesn't matter if your heels are down at a 50 degree angle, 45 degree angle, or even a 10 degree angle - just so long, as your bodies weight is in your heels.
Your heels must be allowed to do their job, which is anchor you into your tack, regardless of the degree. You have to allow that weight to naturally flow, from your head into your seat and into your heels, just by allowing that weight to naturally flow from top to bottom - you cannot grip or pinch with your body, the moment you do that, you've blocked that flow from occuring.
Sit in your saddle, allow your knees to make light contact with your saddle, but do not look to them for a false sense of security. Allow them to open up and allow that weight to flow down. Weight into heels. Don't force it, just allow the weight to naturally flow.
You have to have proper foot placement in your iron as well, to allow the heels to do their job. You have to allow your ankles to relax and act as hinges/shock absorbers. The base of the iron, on the balls of your toes, and then place the outter bar at the tip of your pinky toe and the inner bar at the ball of your big toe.
Then you can find proper calf placement on your horses side. Find the "sweet spot" - remember, as George Morris says, you are not ontop of your horse, you are wrapped around your horse.
Proper foot placement in iron, relax the ankle and allow your bodies weight to flow into your heels. Proper toe angle that will allow you find your sweet spot on your calf for proper calf placement on your horses side.
Think of yourself as lengthening your legs and wrapping them around your horses girth. Solidify yourself in your tack.
When I am out hacking or fox hunting or out on the xc course, I "deepen" myself into my tack this way, so that if something were to occur where my horse may spook, jump, veer - I wont go anywhere, I'm solid.
Weight! Think of it as deepening your weight in your tack from head, into seat, into lower leg and into heels. Don't force it, just allow it to occur. Solidify your lower body, and you'll solidify yourself in your tack.