What are the best techniques for applying semi gloss door paint to achieve a smooth and professional finish?

To achieve a smooth and professional finish when applying semi-gloss door paint, it is important to properly prepare the surface by sanding and cleaning the door. Use a high-quality brush or roller to apply the paint in thin, even coats, working in the direction of the wood grain. Allow each coat to dry completely before applying the next one. Sand lightly between coats to remove any imperfections. Lastly, ensure proper ventilation and temperature control for optimal drying and curing of the paint.