One of my favorite species in the most simplistic setup. (The divider has been removed since this photo, gave the two time to adjust before they paired up
)
If you're going to do a saltwater tank...why not make it exciting? Damsels are old news, and will outgrow the tank depending on the species. They're usually aggressive with little options after being added to a tank. There are plenty of other species that are small enough for a 10-Gallon, and wont cause any major issues in the long run.
-HOB
-Small in-tank filter/Powerhead (For water movement)
-Fair amount of liverock (The more the merrier)
-Time to cycle the tank
-Interesting fish
Can you do more or less? Sure, but I just described this one setup as shown. None of my setups are exactly alike, which shows that there are always plenty of other options.