I tend to trot out the "Karloff Boots" gag every convention because someone always wants a copy. I have a couple of others like that as well, perennial favourites that get produced each and every show. I figured this out after going to Angoulême a few years ago and seeing these French cartoonists produce these incredible sketches in lightning-fast time, then noticing that they produced the same sketch every time. The reason they're so quick to do them is because they can do them in their sleep and know them back to front. A brilliant idea. So I stole it.