Small mirror tiles glued to fishing line with lights behind. This is fantastic.Such a cool easy idea. Would be great in a dorm room. Those after Christmas sales are perfect time to get a light set cheap for this DIY project!
Watercolour triangles let students paint paper with watercolors, wet on wet, similar colors. Let dry and cut into triangles. Students pick triangles and glue down randomly, leaving white around each one. Maybe try with black or other color background?