Spread a drop cloth over the ground outdoors or in a garage or work area. Place the wooden garden object on top of it.
Examine the wood object to locate any raised nails. Place a nail set tool on the nail head, and tap the nail set gently with a hammer to reinsert the nails. If desired, you can countersink all nails just below the wood surface and then fill the top indentation with wood putty. Sand the putty smooth after it dries.
Sand down the entire wooden surface, using a fine-grit sandpaper sheet to smooth out any splinters or rough areas.
Wipe down all surfaces of the wood from top to bottom, using a tack cloth to remove the wood dust, which will interfere with the paint.
Open a can of exterior-grade primer. Dip a paintbrush into the primer and apply it to the wood, using long strokes. Only use enough primer to cover the surface of the wood.
Wait 24 hours to allow the primer to dry completely. Next, open a can of exterior-grade paint in your desired color. Stir the paint up well, using a paint stirrer.
Insert a clean paintbrush into the paint color, and apply it in long strokes to the wood surface until no portion of the primer is visible. Wait an additional 24 hours, and apply a second paint coat to the wooden garden object for added durability.