First of all, you will have to select a rock that you will use to turn into your pet. A river rock is best as it is normally smooth, flat, and rounded. It will also be more symmetrical as compared to other types of rock.
Use steel wool to scrub the rock with dish soap and warm water. This will remove excess dust and debris from the rock and allow the paint you put on to set and stick better. S.O.S. pads work great for this as well. Allow the rock to dry thoroughly.
Use the white paint to place the whites of the eyes onto the rock. The circles do not have to be perfect, as they merely add character. Go ahead and paint the base of the smile as well. Start with just the tip of the brush under the left eye, leaving a little space between the eye and smile. As you move to the right use more pressure to widen your stroke. Once you get to the middle of the smile use less pressure until you are just at the tip of the brush, under the right eye and even with the other side.
Rinse your brush and apply the black paint. Place black dots in the middle of the white eyes to make pupils. Then, use just the tip of the brush to draw in the lines of the teeth in that goofy smile.
Cut the felt to make the shape of a bow-tie, eye brows, mustache, or other character features. Then simply use the craft glue to apply these to your rock. If you are feeling really artistic, you can create some really great pet rocks. Try making a bunny, for example.