I find the branches hang lower when leafed out, so I don't know which ones I will hit my head on until then. I will cut them then while I am thinking about it, and so I only get annoyed once, rather than every time I go under them and hit my head until I get around to it.
Certain ones will have the additional limitation that they have to be cut when my wife isn't around to complain, otherwise I am stuck walking into them.
While live branches for certain trees should be cut at certain times of the year, as listed above, every article on pruning I have read says dead wood can be removed at any time.
There's been a few which have been best served by very radical pruning, at about an inch above the ground, full across. But then we're back to your other question...