Which holly? What type of pruning / how much pruning are we talking about?

My inlaws have a hedge of hollies, perhaps blue princess & prince, or something similar. We cut branches in late fall to use for holiday decorations, and then in the spring, once danger of really cold, dry weather has passed, any winter damage gets pruned off before new growth starts. It seems to thrive with this treatment, but I don't know what the official recommendations are. We are a few miles north of Concord.

What you've been doing is perfectly fine. It might be a better idea to remember when you should NOT prune. Avoid late summer through fall for any substantial pruning or shearing.

Damaged or broken branches should be removed at any time.

Mainly interested in shaping,already remove dead and damaged at anytime