This is one of my holiday cards based on dogs that I've met at the dog park when I've been there with my dogs. It's called "Running through the Snow."
I paint digitally only when I'm looking for the immediacy of having the image in the computer to use for printing (such as a greeting card). The application, Painter, has a robust toolset that enables artists to "paint" in a variety of virtual "mediums." Painter simulates media from watercolor, oil, pastel painting to charcoal, ink and pencil drawings. The user can layer color as in real-life painting and can set the background texture to be as smooth as paper or as rough as canvas. The effects obviously do not replace the real thing in terms of tactile depth and texture (and to some extent, color), but one can create some interesting and compelling works using this program along with a graphics tablet.
My digital watercolors are mostly of dogs (and a few cats) that I use for greeting card designs. If you're interested in seeing more cards and perhaps purchasing some, please visit spiderink.etsy.com.