I've been finding that just simply mocking up the sites/apps I'm building or even just pieces of their functionality has helped me refine what I feel is implementation of good user experience. The marker comes down to "Would I use that?", and more often than not, as fast as I can get a page up it's no match for a mockup that comes to fruition even quicker. Check out Balsamiq (http://www.balsamiq.com/) for the app that I choose to use. I also lurk ux.stackexchange.com, as mtrn suggested it's a great resource.