Before drilling a hole in your pot, you must know its material. If you have a plastic pot, you can puncture the bottom with scissors.
Gather your supplies. The American Ceramic Society recommends ceramic or carbide-tipped drill bits for ceramic and clay pots
You'll also need a soft, flat surface for the pot, like foam, a bowl of water or spray bottle to wet the pot, tape, and safety gear like goggles, a respirator or mask, ear protection, etc.
Ceramic and clay can contain up to 50% free crystalline silica, which can scar lung tissue if inhaled.
After gathering your tools and protective gear, start drilling. The American Ceramic Society advises going slowly and stopping often to check progress.
Tape the pot's back in an X-shape to mark where the hole will go. For those without drill experience, this will improve aim and prevent sliding.