Damsels are fine to add. Provided any other fish you add afterwards are bigger.
I use damsels to buffer new tanks until they are well established.
Then add the new fish.
Yea, clowns are great. Cute, pretty and active.
You cant go wrong with a goby either. Strange fish, can get a little large but for the most part non-aggresive. Plus they clean your sand, but you need a good cover on your tank, or a good distance from the water to the top of the tank cause' goby's are prone to jumping.
I got a rock beauty about 6 month into my tank and she has been just adorable. No problems with aggrestion or anything else. She keeps the algee down and is very colourful.