Fill in holes for both nails and wood imprfections/damage.

You can fill holes with an exterior wood filler. Simply just use your finger or a putty knife. Fill space completely. It is okay to have excess, as you will sand it in the next step.

Why fill in holes? Filling in holes can protect imperfections in wood where weather may decay the integrity of the wood faster. Additionally, filing in the holes provides a cleaner look when finished.