How do you properly apply polyurethane to stained wood for a smooth and durable finish?

To properly apply polyurethane to stained wood for a smooth and durable finish, follow these steps:

1. Sand the wood surface to remove any imperfections and ensure a smooth finish.
2. Apply a coat of stain to the wood and allow it to dry completely.
3. Use a high-quality brush to apply a thin, even coat of polyurethane to the stained wood, following the grain of the wood.
4. Allow the first coat to dry completely, then lightly sand the surface with fine-grit sandpaper.
5. Apply a second coat of polyurethane in the same manner as the first coat.
6. Repeat the process for additional coats, if desired, allowing each coat to dry completely before sanding and applying the next coat.
7. Once the final coat is dry, lightly sand the surface with fine-grit sandpaper and apply a final coat of polyurethane for added protection and a smooth finish.