How can I properly treat lumber for outdoor use to ensure its longevity and durability?

To properly treat lumber for outdoor use, you can apply a wood preservative or sealant to protect it from moisture, insects, and decay. Make sure to follow the manufacturer's instructions for application and reapplication as needed. Additionally, consider using pressure-treated lumber or naturally rot-resistant wood species for added durability. Regular maintenance, such as cleaning and resealing, can also help prolong the lifespan of outdoor lumber.