Sometimes I get shaky hands... Really bad... Like I can barely hold a joint, or anything else. But they don't shake unless I'm trying to use them for something delicate that i know I can break if I squeeze too hard. If I know I can grip it tight, there's no shake. Its just hard for me to apply gentle amounts of pressure with my fingers when I've smoked too much, to the point of virtual impossibility without my hands shaking like crazy.

Never really twitch or shake in any other way, though.