Check between the boards to make sure there are not small rocks, sticks or other items in the way.
Sand in the direction of the grain. Use a pole sander, which allows you to stand while you sand, or get on your knees and sand with a hand sander.
If you have a pressure washer, use that! It’ll get all of the tiny dirt particles out of the wood and ensure a cleaner finish. Follow the directions on the deck cleaner you choose to use. Some will require you to wet the deck before washing it, others will want you to apply the product directly to the wood. Allow the cleaner to soak into the deck according to the instructions. Rinse the deck after cleaning it if necessary.
Once dry, sand the deck with a fine-grit sandpaper to ensure the stain absorbs in the wood.
Test the stain color in a small part of your deck to ensure it is the color you want.
Use a water repellent stain that also provides protection against mildew.
Brush from one end of the board to the other, using long and even strokes. Spread the stain smoothly. You do not want it to puddle.
