I'm basically in the same boat as you! Last week, I decided to utilize the drop ceilings in the same kind of way.
I'm definitely making paper lanterns to hang around my living room. In fear of putting lights or anything in there, I'm going to spray them with this glitter sealant I have so they catch light and shimmer.
I also hung some old icicle lights throughout my ceiling along one wall where I have a mirror. The glow of the blue lights off of the mirror look amazing!
My sis-in-law has drop ceilings also, and she wanted to jazz her bedroom up. She went to Joann's and bought a few yards of fabric and attached them to the ceiling with paper clips so that they draped downward and she created this wave affect behind her bed. It looks like she has a 4-poster bed without the posters! That is going to be my next venture in my bedroom.
This thread is awesome though! I hope more people with drop ceilings give some input!