but yes it takes a lot of hard work and time to come up with puns which are genuinely fresh and funny. Some authors, like Piers Anthony, who use a lot of puns have turned their humor into a kind of promo tool too. for some of his books you'll find he's included puns sent in by his readers (with an acknowledgement to them in the book.) Ingenious in that he has to spend less time making them up and he gives the readers a thrill to see their stuff being published.
Kinda cool, if you write a lot of that style of humor.