"Bad artists copy. Good artists steal. " - Picasso

Seriously... probably looking at examples of beautifully design sites and getting some 'insipration' from them. Articles on smashing magazine are pretty good, http://www.smashingmagazine.com/

And I've recently found http://www.metalabdesign.com/

I reckon it just boils down to practice and lots of redoing your design over and over again. I don't like doing it because it seems like a waste of time compared to the amount of code I could have written.