I wrote about this once before, but thought I'd add just a bit to my previous post.
Bookstore signings are not my favorites unless I can give a talk, either about the inspiration for the book I'm promoting, or something about writing. Standing by a table with my books, trying to get people's attention who are actively trying to avoid eye-contact is not my idea of fun.
I do enjoy craft fairs because a lot of the people who attend have never seen a "real live author" and it often surprises them to know I actually wrote the books I've got displayed on my table. (I've gone to enough of those that I've purchased my own tent and folding table.)
Big mystery conventions are fun, but unless you're a well-known writer, book sales won't come anywhere near paying for what it cost to go. You will have fun though and it is tax deductible.
Smaller conventions are fun because you really get to know the mystery fans. My favorite is Mayhem in the Midlands.
Speaking in a library is always fun and if they let you sell your books, usually you'll do well.
This year I've been asked to speak to a group of retired women and after that to a Lion's Club. Another fun group is Rotary.
For me, what works best is to give some kind of humorous talk that has something to do with your books. If you make them laugh, you'll sell books.
Those are the things I like to do.