Proper exterior caulking around your home seals out moisture and outside air while reducing energy costs and preventing costly repairs. It will also help keep out insects and small creatures seeking food, shelter and warmth. With some basic tools, supplies and a little work, your windows will be airtight and ready for the season.
Check to see if any air flows through your closed windows. Also look at the caulk on the outside of the window. If there are visible gaps and cracks, it's time to re-caulk.
Be careful not to damage the door or window frame.
Although this seems trivial, the proper cut will have significant impact on how thick and wide your caulk will be applied.
...and you are ready to go.
Use a step ladder if needed.
To get a really smooth finish, wet your finger and drag it along the bead of caulking compound.
If you're using paintable caulk, let the compound set for the recommended drying time before painting.