To achieve long-lasting results when staining a deck, start by thoroughly preparing the surface by cleaning it, removing any debris, and ensuring it dries completely. Next, choose a high-quality, weather-resistant stain to enhance durability. Apply the stain evenly using a brush, roller, or sprayer, and allow sufficient time for it to dry before using the deck. To maintain the finish and protect the deck over time, reapply the stain as needed.