1. Had a life-changing experience getting worked over in a small limits game & learned that he needed to improve.
2. Played pot-limit in Europe
3. Derives a lot of improvement from non-poker games (I play gin, bridge, chess, and have gambled on everything)
4. Heeds Daniel Negreanu's advice (see 2 posts down)
The thing I found most interesting was a short reference to the look he gets when he calls out people's hands. I used to do this all the time (e.g. "Okay, I have a flush, show me your trips") and it would completely freak people out, like I had some super power. This is a great way of knowing the quality of your opponents. When Glaze and I used to get bent over in a 5-10 Omaha8 game, the whole table would say, "ok Craig show me your A-2 with the ignorant end of the staight" I would think "How did they know?" Conversely, when people don't know how you knew what they held, you know you have a sucker. I've quit doing it now, because it sometimes has the effect of scaring off the customers.
Random thoughts from a lawyer, an accountant, a commodities trader, an ex-Marine and a WSOP Main Event money finisher that don't know as much as they wish they did...