Stain in your favorite color and seal with a UV protectant top coat.

I used angle iron horizontally to create a lip for the face to sit on the top of the existing gate. I measured from the bottom of the existing gate to the top and that determined the placement of the angle iron. I drilled/screwed through the angle iron into the top of the gate to secure it. I added additional screws from the back to the front for more stability, just make sure they are not so long they protrude through the front.

Embellish with clavos, metal straps, handle, hinges, etc. Have fun with it!