Load up a small amount of drywall mud onto a trowel. It's better to work with thin coats or mud, rather than a big, gloppy mess. To make cleanup easier, wear a pair of rubber gloves.
Smooth the mud over the dimple, using a light hand to gently spread it over the dimple. You may need to use a little extra to fill in the depression on the dimple. Use the edge of the trowel to scrape away any excess mud. Let the mud dry according to the package instructions, usually within an hour.
Sand down the drywall mud, using a fine grade of sandpaper and a block sander. The patched surface should be as smooth and even as the rest of the wall. Clean sanded areas with a damp cloth.
Paint over the area, using a small paintbrush to apply a light, thin coat. You can always apply a second coat if necessary. Catch any drips as they occur and smooth out the surface. Let the paint dry for about two to four hours.