I may not know much but I'm pretty good at making worm gears now and their associated spur gear partner by hand. Probably because I've made so many mistakes on previous attempts.
They're still a pain in the arse though.
I've been working on another model for a friend's birthday. I'll update with pics after the event.
UPDATE: I've just tried to make another worm and spur gear which was a complete disaster. It looks like my smugness got the better of me. Time to learn some humility.