I've been cleaning closets and selling a lot of stuff on eBay for the past few months. I've learned a few things about dealing with buyers; one is that if a buyer asks a bunch of questions and seems to be a nervous nellie, I'll now block him or her. I've learned that if they're the high bidder they turn out to be far more trouble than they're worth.

Any other eBaying tips from a seller's POV?