Hand painted tree rings - would recommend putting all tree rings on a board (which could be painted a coordinating color to add pop to the art piece. Really neat idea for after school kids. Might just do 9 rings in a square frame!
Check out these great driftwood sailboats with sails made out of nautical-look fabric scraps. I think you could also use long breadbaskets as the boat bottoms and put the bread for your buffet in them!