I think we're going to see a lot more interesting work when tools like ThinkFish are perfected. I use the airbrush or pencil tool to make a mockup and work from that. Often it's just a matter of fiddling with fonts and fills. I try to keep the images relatively simple as they are going to be both scaled down and have their colors reduced. One of the major problems I find with the Web is that people don't optimize their graphics for either color or size.
Net result is a slow loading site with ugly graphics.
There are any number of good books explaining how to optimize graphics and a few extra minutes spent doing it will really make a difference for your visitors. My art is primarily in anime style. I worked in the Japanese animation industry for 14 years and this style has become my own. I try not to be too pretentious when I do art. I like to work with strong colors and blending.