Ornament balls
I buy some of the clear glass ornaments every year, along with some glittery paint from the craft store. The students choose 2 colors that they would like to mix, you pour 2 lines of each color into the top of the glass ornament, put a paper towel over the hole, and then shake it really well. Sometimes you need a little (I stress little) water dripped into the ball to get the paint to swish around more. The end results are beautiful. I either have them write their name on it, or I do it in my "teacher writing".