As I've stated many times, I am an advocate for dormant season pruning--whether the tree is a conifer or a hardwood.
Aesthetic pruning to facilitate mowing is certainly acceptable as long as you do not remove too many branches--again, I would wait to prune until the dormant season (i.e., late fall through late winter). The best way to prune a tree is a via a pruning saw--not a chainsaw!!!
Here are several good publications to help you get started with your pruning project:
Best of luck!