What are the best techniques for applying primer gray paint to achieve a smooth and professional finish?

To achieve a smooth and professional finish when applying primer gray paint, it is important to properly prepare the surface by sanding and cleaning it beforehand. Use a high-quality paintbrush or roller to apply the primer in thin, even coats, allowing each coat to dry completely before applying the next. Sand lightly between coats to smooth out any imperfections. Additionally, consider using a primer specifically designed for smooth finishes to help achieve the desired result.