I can relate, when I am in a really bad stage the ractions are sometimes like "oh look it tries to speak". So I started to keep it quick, unexpected and smart. If it is actually funny and quick enough not even a stutter can kill the joke, just like batman. So I don't know how you can learn that, if you could bring yourself in a situation in which you meet constantly new people practicing it might be easier because it is a fresh start everytime. I did that by backpacking and talked with fellow travelers but it was also sometimes awful.