Step 1: Print off the templates for the cacti shapes. Scale them to your desired size. For the tallest cacti, if you would like the same size, you will have to copy the template at your local printer on their engineering sized prints.
Step 2: Cut out the template shapes.
Step 3: Trace the shapes onto cardboard.
Step 4: Cut out the shapes with a knife or scissors.
Step 5: Paint the cardboard if desired.
Step 6: If you use spray paint, let it dry for at least 24 hours.
Step 7: Add patterns onto the cardboard. This is the fun part!
Step 8: Cover the hole in the pot with tape.
Step 9: Fill the pot with rice. Tip: to save on using too much rice, I cut out a circular piece of cardboard to the shape of the pot a few inches below and filled the rice on top of that.
Step 10: Put your cactus pieces together and insert into the pots.