If you have extra time (or not too many cobwebs), dust the tops of picture frames, mirrors, etc. that are hanging on the walls. And, since you already have your vacuum out, you can dust along the top of the door frames. This doesn't take very long to do!
Remember, if you are feeling overwhelmed or you don't have much time to devote to this task today, just focus on the dirtiest or most used rooms in your home.