I decided to post this here as an oblique response to my own earlier post. And why waste my writing solely on someone else’s website? (Why not waste it here, too?)
I don’t know how much it would help to try any particular techniques, or specific kinds of things to say, or joke structures, that other people suggest. Because what makes you funny is probably exactly what makes you unique. What works for one person doesn’t necessarily work for someone else, obviously.
So the key is being yourself.
Turn off the internal censor.
Just say what you think is funny or (better) whatever occurs to you naturally in any given situation. Don’t try to be funny.
You should have an inner confidence that you’re funny, but you also shouldn’t expect anyone else to think you’re funny.
Self-deprecation is good, but not necessarily required. You can say something funny about something else without drawing attention to your own humility (real or false).
That said, considering how you describe yourself, deadpan humor may be the key.
Since you mention you’re funny in print but not as much in person, a funny thing to say if you bomb might be “That was hilarious on paper,” or “That would have gotten a huge laugh on MetaFilter,” or “That was way funnier when I submitted it to the New Yorker.” For example.
My favorite running gag is, when someone says something unintelligible, or makes an irreproducible sound, to say “That’s what I always say.” The underlying humor (to me) is that what I always say is “That’s what I always say.”
Clearly I’m a fan of the self-referential and the absurd. And, frankly, I’m far more interested in entertaining myself than anyone else. But that seems to work for me most of the time.
(This was my answer to an AskMetaFilter post.)