Indicators of a crackpot paper

From Scott Aaronson: Ten Signs a Claimed Mathematical Breakthrough is Wrong.

I've often wondered how to decide whether a paper or book is worth my time to read. People who like a certain paper or book can always tell me that I shouldn't judge it until I read it. But I need some estimate of its quality/creativity/interestingness before I start. I've decided to be biased towards shorter things and more well-known things. I don't see any good alternative, unfortunately.