Pet portraits are primarily done in graphite or colored pencil on 11×14 Bristol Board. I have experimented a bit with other mediums, but so far those are my favorites. (See Reflective Kitty for an example of an egg tempera portrait!)
This dachshund image, “Clarke”, I created with graphite and then added a bit of aquarelle (watercolor pencil) for the colors, since he has such neat merle markings. I think the overall effect is very nice.
The price for a pet portrait depends on the medium and the quality of the image I have to work from. I work from photos, so no, your pet doesn’t have to sit still for hours on end. I can take photos or use yours. I have done some portraits from very poor quality photos, which can be nice if it’s a portrait of a pet that has passed on and you don’t have any good recent photos, but keep in mind that the poorer the quality of the image, the harder it is to make it look like your pet. For living pets a good recent photo is most helpful. You can even email a digital photo.