Keep the drafts out this winter!
Make sure the areas to be caulked are clean. Start by washing with mild detergent and dry well. Use masking tape to protect walls and obtain a straight edge.
Cut the nozzle of a new tube of caulking at a 45-degree angle. The opening should not exceed a quarter inch in diameter.
Position the tip at a 45-degree angle to the seam to be caulked. Move the gun slowly, keeping a steady pressure on the caulking gun trigger.
When you reach the end of a seam, push the nozzle into the caulking to cut it off and twist it sharply as you pull away.
You needn't smooth out the caulk because it will shrink as it dries. If you do smooth it, use the back of a spoon dipped in mineral spirits or, if using latex caulk, use your finger dipped in water.