How long should I make mine or how long should they be to provide adequate protection to the heads and shafts? Also how big of a pom do you think is good?

I have the 2006 Ryder Cup set with 5" driver pom-pom
Love them. Can't wait to get new bag this winter and order new covers

get the extra length on the socks (+2) I beleive.. large poms are nice but eventually when they start to stretch a little like mine, the large poms will nearly pull socks off from the weight. It was only a problem when I went from larger to smaller fairway woods.

I recommend Jan Craigs