So I own draft horses and because they're draft it's REALLY hard to find a reliable and quality trimmer/farrier that is willing to do drafts. I've been trying to get my 2 year old gelding, Sam, done every 6 weeks, but with not a lot of options for farriers, it's difficult. I've been looking into trimming his hooves myself, and would like some advice... His hind hooves are really worrying me. I think a lot of it is from how he stands, but I'll submit photos and let you have at it...
You can see in this picture that he stands funny with his back legs
He seems to swing his hing legs "in" and "under" himself, walking and standing...
I find it interesting that farriers don't like drafts. While they're big, I find them generally pretty good to do - & big enough not to have to bend my back so much!
Can't see any obvious flaring there, but not great pics for critique - check out below link. Is he toed in behind? Is the right leg turned in more? I'd be inclined to get a bodyworker come check him out too.
Horses tend to weight the outsides of their backs when resting - so domestic horses that don't do lots of exercise often grow higher on the insides, though couldn't say there's great evidence of this from those pics - the right may be higher on the inside but hard to tell from that angle.
Basically re trimming, I'd be just following the sole plane as to wall height and keeping toes under control, which on the right at least has become stretched forward. But I'd learn all the theory - hoof/limb form & function, etc, and if at all possible, I'd get yourself some lessons or at least to a clinic with a good farrier/trimmer if you're going to take on the job yourself. If you can't do that, then at least Pete Ramey's dvd set is a good investment I reckon.