Attach fine-grain sandpaper to your sanding block or finish sander. Sanding with your hand alone, instead of using a block, can leave noticeable irregularities in the surface of your work.
Sand the entire surface of your piece smooth. If your piece has been exposed to the elements long enough to turn the surface gray, sand until you remove the gray patina from the surface of the wood.
Remove the sanding dust from your piece with a tack cloth. Turn and fold the tack cloth frequently to remove as much dust as possible.
Apply a small amount of teak oil to a clean, lint-free cloth. Rub the oil onto the surface of the wood with a circular motion.
Continue to apply oil until there is an even coat over the entire surface of the piece. Allow the oil to dry overnight.