I can't do punchline things at all!! I only try them with my closest friends, sister or SO - they think it's hilarious even when my delivery falls flat, because if I'm giggling it infects them, too :) other than that I rely on non-sequitur humor, puns... lots of puns. Puns are specific words, which can be tricky, BUT you can sneak into hard-to-pronounce sounds by using filler words or synonyms around them, and nobody focuses on the filler or synonyms - they just remember the pun. also, a lot of humor can be accomplished by twisting around what someone just said - substituting a word, or placing emphasis elsewhere - and echoing a phrase makes it a million times easier to say, so that sort of fast-paced timing actually works to my benefit