i will offer my two cents:
1. STANCE, make sure you feel even pressure across the whole of your feet, also if you're really struggling forget the park type stance and bend your knees more and your hands up and shoulders up over your hips a bit (this will make sure that not all the forward balance is coming from the ankle muscles)
2. BOOT FIT, i know its been said but make sure your boots actually fit, visit a few different fitters to get several opinions, getting the right boot setup can take years of adjustments. (also find a shop which has the pressure reader for feet and boots this helps a lot with things like canting stance and stretches you should do)
CUSTOM LINERS AND FOOTBEDS - if you have the cash seriously look into these
3. SOCKS, going through the obvious but use 1, ski specific sock (correct areas of padding, preferably fairly thin, comfort and warmth does is not proportional to sock thickness. make sure your socks are not cotton, choose either a synthetic or merino wool pair (merino wool is da shit anti bacterial high wicking properties etc. look it up) this will help take the sweat away from your skin and prevent chaffage, the antibacterial properties of merino might also help prevent inflamation but i'm not sure.
4. LANDING BACKSEAT, really practice getting good straight airs and popping well so you land evenly on your feet as sated above in STANCE. Do lots of quad work especially squats and stuff to help smoother landings
5. ANTI INFLAMATORIES, after a hard days shredding if your skins are all bruised up and sore rub an antiinflamatory cream into them to help ease swelling
6. BUCKLING BOOTS it is really important to buckle your boots properly so your feet rest correctly in the boot. get your heel to the back of the boot, (not sure with FTs but i'll have a go from a picture), bottom buckle first then work your way up tightening so the hold is firm but not uncomfortable, power strap should be tight, when you done your warm up lap you should be able to tighten your buckles a bit more. I personally have my boots super tight for performance and unbuckle on lifts. buckling will different for everyone so play around loosening and tightening to see what works(for 3 piece boots with four buckles bottom buckle closest to ankle joint first then toes then second from top then top then strap
7. SHAVE ANKLE HAIR TO REDUCE FRICTION?
hopefully this covers all the potential problems, btw its nearly two in the morning in the uk and i have work tomorrow, glad to help though