What are the best techniques for applying floor stain to achieve a professional finish?

The best techniques for applying floor stain to achieve a professional finish include properly preparing the surface by sanding and cleaning it, applying the stain evenly with a brush or rag in the direction of the wood grain, allowing the stain to penetrate for the recommended time, and wiping off any excess stain to avoid blotches. Additionally, applying a topcoat of sealant or polyurethane can help protect the stained floor and enhance its appearance.