Zel finds rocks to be very exciting, so any activity involving rocks is a hit with him. On a sunny day, I sent Zel out with his Daddy and a bucket to collect some rocks from around our apartment building (I stayed home so I could exercise without a toddler climbing on top of me). We put our bucket of rocks away for a rainy day, when we could use them to paint on.
Kids love painting, but there is something about painting on items other than paper that makes it extra exciting. For Zel, it was a fun sensory experience too. If you do this activity indoors, I would suggest putting down some plastic or a blanket to cover the floor, especially if you have a toddler. Zel loves to throw rocks, so having the plastic saved the carpet. We used tempera paint and I gave him old applesauce cups to mix the paint in. We selected a few rocks and began painting.
Eventually, Zel began to explore methods of getting paint on the rocks other than using a paintbrush. First, he finger painted on the rocks. Then, he discovered that he could put the rocks into the paint cups to cover them with paint. This proved to be even more fun. He then began pouring the rocks back and forth between the various paint cups. This was the most fun yet.
I added a layer of glitter glue to one of the rocks and used a paint pen to write his name on it.