You must firstly have the desire to improve, the hunger to hunt for better images...
It is a strange mental state, but the more i see other folks having nicer photo than mine, the more I push myself to a higher level.......
I am another one that believes in the photo critique of photo.net.
There are just so many talents there, and most of the advice given are correct.
You can learn even more by looking at other ppl's "mistakes"

btw I don't suscribe to the notion that you need to spend more to push yourself to improve.