Here is a Youtube video I had sent to me about a year ago by one of my many contacts on flickr.com. It’s a bit wordy and quite long, but the information is all good. Increase to full screen to see the cursor moving … that way all the talk will make more sense. Other than that, it’s a good tutorial in Photoshop. Most of the techniques are transferable to GIMP, so even I can use this information to my advantage. I hope you also can.