Loom loops (otherwise known as potholder loops)
Terra Cotta planters
Dye (if you're Ombre dipping them. I used Ritt navy blue on mine.)
Simply flip the planter over and loop around the base till you have the desired amount of texture and layering you want. The loops at the end of my base are smaller, this keeps them all in place from popping off. If you have issues with them falling off ( I haven't) you can do a small bead of hot glue on the last one.
For the Ombre dyed one create small shallow dye bath, dampen the pot with loops on in water so the dye can climb up the loops creating the Ombre effect. Let the pot sit in the dye bath till the color you like is reached and then lightly rise off and let dry. So many color combinations are possible with this.