I think my biggest leak is...

[Randy Burgess]

Hmm. The technical stuff Ed is talking about is invaluable--but I've always felt (and observed) that non-technical leaks are at least as dangerous for studious recreational players.

Someone may be a winning low-limit hold'em player when he's mentally sharp---but if he persists in playing when tired, on tilt, etc., he risks losing many more chips than from all his technical errors combined. For many of us, coping with our emotional reaction to gambling is still the hardest part of the game. The capacity for self-deception here is huge.

Aside from that, I like very much Ed's suggestion to prioritize your learning. On a technical level, nothing could be more important for the studious player. I also like the observation (from his book, this time) that our brains aren't built to handle randomness, meaning we are liable to draw the wrong conclusions from short-term experience. If you don't work from a sound technical basis, you leave yourself vulnerable to subjectivity; and subjectivity leads to tilt.