Play some music and have the kids circle the shirts while spraying them with the water-paints as they go. When the music stops, they have to switch colors with the players next to them. Keep playing until all of the shirts have been sprayed with a colorful design. Leave the shirts on the line until they are dry, then hand them out as party favors. Play some music. Have each kid stand in front of a station and begin creating a mural. When the music stops, you should have everyone move to a new station to continue the work already created on that mural. Play is done when everyone has had a turn at each station.