I absolutely love this mini cactus as a gift idea and the best thing about it is that you can't kill it! Here's how to make it via Salt and Pepper Moms.
Here is what you'll need:
First wash your rocks and make sure all the dirt has been rinsed off.
Then sort your rocks. I chose a long rock and two round shaped rocks per pot. You want to have dimension.
Paint your pots and let them dry. After they were done I sprayed them with a sealant. I then painted my 3 rocks different shades of green and tried making them all look like different cacti.
Once the pots are dry and the cacti are done, fill your pots with moss. Place the rocks in the pot where you want them. Then fill in with tiny rocks to hold your cactus in place. That's it! Look how adorable they are!