Posting hands helped me tremendously. Also, one thing that I feel has improved my game more than most anything else is coming up with a couple of quick strategies/scenarios the moment I see my hole cards. In other words, I'm trying to think ahead and plan what to do based on position, chip counts, the reads I have on other players, both pre and post flop.
For example, let's say I'm thinking of raising somewhere in MP pre-flop. Before I do this, I should be thinking about what I'm going to do if somebody 3-bets me. I'll try to ask myself questions like these: if I do get 3-bet, who is doing it and what do I know about them? If there's an aggro in later position who likes to punish limpers and 3-bets constantly, should I try and open a pot with a speculative hand or just fold and wait for a premium pair?
Alternately, if I have enough chips, should I go ahead and call a 3-bet if it's just going to be me and him HU and see a flop? Have I seen him fold to a 4-bet in the past and should I try that since he's likely raising with junk the majority of the time? Or, what if he folds and both blinds call, and the SB is a passive nit who never raises or bets with the nuts, should I c-bet the flop? This might seem like an awful lot to do, but with practice you will run through questions like these within seconds.
When I first started I was flying blind, I had no strategy at all and didn't do any thinking beyond the cards I had in front of me and my results showed it. I haven't done very much studying, I still have a ton of leaks in my game, but I'm still far ahead of where I thought I would be 6 months after starting.