I took a very good course on painting pet portraits by Cheryl Butler, called "Fur Babies". It is a five week online course, but you can do it at your own pace. Brushes and techniques are all supplied in the weekly PDF files. To start with you do need a good image. The one above was taken with a flash, so the lighting is pretty good and the background blurred. The background blender brush is worth the price of the whole course by itself. You have to be really committed to doing portraits, because they can take you anywhere from 6 to 8 hours. The hardest part, the whiskers! If you are interested, you can go to www.bellefleurtextures.com, for more information.
Nature Images and More!