Setting type drywall mud is really useful for quick repairs. It's basically plaster of paris with fillers and retarders to lengthen the set time, and it can be sanded and ready for paint in 30 minutes. I've found that a small plastic bag is really handy for mixing up a small batch with no mess. Just put a half cup or so of powdered compound in a sandwich bag, add in some water, and squish it with your fingers to mix it until it's smooth. Add a little more water if you need to. Twist the bag shut, cut a corner off, and squeeze the compound where you need it.