Wedge the door half open, remove the handle and cover the floor with newspaper. A door is likely to have collected dirt and grease, so you need to thoroughly wash and abrade with wet and dry paper with a mild detergent.
If you have a brand new bare wood door, you will need to treat it with a wood primer before painting.
For best results, a door needs to be painted in a certain order. Start with the edges, then move on to the mouldings and panels, using the edge of the brush for the recesses. On the flatter surfaces, use the flat of the brush to cover the surface with paint, brush left and right, followed by up and down strokes to spread the paint evenly.
Once you have done the inlays, move on to the rest of the door. First, paint the vertical centre panels, followed by the horizontals, before finishing with the long side strips.
To achieve a good finish, load the brush generously and spread the paint across the surface, before finishing with long, gentle brush strokes. Do not rework the paint once it’s started to dry as this will create an uneven finish.