Digital Painting

I'm been trying to get myself to do some digital paintings. Its often difficult to find a really good tutorial online for them. But today I found a pretty good one to make a quick and dirty planet. Here's a link to the original tutorial : http://gallery.artofgregmartin.com/tuts_arts/making_a_planet.html

And here's a sample of my attempt at it:

It was pretty easy step by step tutorial and a fun read. I hope I can find more like this. Its done by Greg Martin and he has a large gallery of other paintings he's done. Some really amazing pieces.