I am new at trimming and a bit OCD about things, I figured out what is probably obvious to most, which is - to ensure that your horse lands heel first (for front hooves)- film them walking toward the camera on a flat surface, preferabley hard dirt, on ground of opposite color as their feet! I am slow on the up-take, so I put my DH through several filmings until I was 100% satified (DH kept saying it was clearly heel first at .125 playback speed, side view - but I just wanted a tiny bit "more" confirmation). Side view is nice and gets all 4's, but toward you removes any and all doubt w respect to the fronts (in slow mo).
I started obsessing on this aspect after watching part of the dvd's I got (under the horse), b/c I have to trim my baby's feet - I do not want to make a mistake, set something in motion, be responsible for problems, not detect something. Yada, yada. No telling what will be my next hoof stuff "obsession". :)