So far I have one with rice and food coloring, one with baby oil and water with food coloring, soap and water with food coloring, and water and sequins. I just super glue the lids on, and then wrap with electrical tape. So far, my a Little Peanut has been interested in shaking the rice bottle, and the sequin bottle seems to catch her attention. I am going to make a few more in smaller bottles that may be a better fit for her hands. I'll keep you posted when I come up with some more ideas.
