1. Choose a large bit size. If working with ceramic or terra-cotta, use a special tile bit. "Take a nail and make one little ding where you want to drill the hole to prevent the bit from slipping and nicking the pot," advises Welch.
2. Place the bit in the ding and line up the drill so it is exactly perpendicular to the pot.
3. Press the drill firmly into the container and then drill through the container in a single motion. To prevent your drill bit from slipping around when working with metal containers, first make a shallow hole with a very small drill bit and then drill completely through the pot with the larger bit.