How can I buff a polyurethane finish to achieve a smooth and glossy surface on my project?

To buff a polyurethane finish for a smooth and glossy surface, start by sanding the surface with fine-grit sandpaper to remove any imperfections. Then, use a polishing compound and a buffing pad to gently buff the surface in circular motions. Repeat the process until you achieve the desired level of glossiness. Finally, wipe down the surface with a clean cloth to remove any residue.