Despite filing down my toenails regularly (I even carry an emery board in my equipment bag) I still manage to ruin socks primarily where the big toe nail saws through the fabric (same problem with my bike socks, in fact).
I tried taping a piece of white medical splint wrap tape over the offending nails. Too soon to know whether its going to work, but the tape left a sticky mess behind that caused my after-ski socks to stick to my toe.
Any bears have a brilliant simple solution they employ to prevent this nuisance? I shedded one last year and thought that toe wouldn't be a problem for a while, but the replacement grew back really quickly.