By Gene and
Step 1 : Prepare the wood surface of the brackets
Before finishing brackets sand them lightly to smooth the surface. This is easier to do before they're installed. To get into intricate curved areas make sanding strips by cutting sandpaper the width of masking tape. Tape the backside of the sandpaper to the sticky side of the tape and use the strips as if it were dental floss. When the surfaces of the bracket are smooth and uniformly sanded, they can be finished before or after installation.
Step 2 : Predrill mounting holes in the brackets
Hold a bracket in place centered on the surface where it will be installed. Choose an inconspicuous location at its base where you can drill a mounting hole for a nail. Predrill a hole or holes (depending on the width of the bracket).
Step 3 : Install the bracket
Apply a small bead of construction adhesive with a caulk gun to the back of the bracket, place the bracket in position and push it tight against the surface.
Drive a nail through the mounting hole to hold the bracket in place until the adhesive dries. Then use a nail set to tap the nail below the surface of the wood. Fill the nail hole with a quick drying filler and sand it smooth.