Use your drill to make a hole in the bottom of your rain barrel. Make sure this barrel has a diameter of 3/4 inch, the same diameter as your wooden cylinder. Additionally, make sure the hole is roughly an inch above the bottom of the barrel.
Drill a hole through the middle of your wooden cylinder. Make sure the hole is the same size as the cork you will use for the spigot.
Insert one end of your wooden cylinder into the hole at the bottom of the rain barrel. The cylinder should fit securely into the hole.
Apply silicone seal to the cylinder on either side of the hole. This will further secure the cylinder to the rain barrel.
Insert the cork into the wooden cylinder on the outside of the rain barrel.
Use your new spigot by removing the cork when the rain barrel is full. Reinsert the cork when you have emptied the rain barrel to your satisfaction.