Drainage holes are the most critical part of any good ceramic flowerpot. If your pot doesn't have a hole (or doesn't have enough holes), you can easily fix the problem. Simply drill another hole in the pot.
What You'll Need to Cut a Hole
To cut or drill a hole in the bottom of a pot for drainage, all you need is masking tape and a ceramic or masonry bit for your drill. These bits come in assorted sizes, so find the one that best suits your needs. Use a smaller bit, about a 3/16-inch bit to drill a guide hole first. A pilot hole will cut down on the larger bit jumping around. The pilot hole will also reduce the heat and the pot's potential for cracking.
How to Cut or Drill a Drainage Hole
Use masking tape to mark an "x" where you want to drill. This keeps the bit from slipping. Using a variable speed drill and your ceramic/masonry bit, drill your guide hole. Then switch to a larger bit and begin drilling your hole. Drill slowly and run water from a garden hose on the area you're drilling to reduce the heat.
Use a rubber mat or stack of newspapers to cut down on vibrations. Don't force the drill, and take your time.