Secure a second decorative wood handrail to the wall on the opposite side of your staircase. The second stair railing adds interest and eye-appeal to the bare wall and, more importantly, provides additional safety for people as they go up or down the stairs. Orienting the handrail on its side can add finger-hold and save space on narrow stairs.
Measure the banister height and mark that distance above the stair treads at the top and bottom stair. Use a level to draw a vertical line at each mark and connect them with a chalk line for the stair railing.
Locate all the wall studs along the length of the stair rail with an electronic stud finder. Mark each for use in securing a mounting strip directly to the studs for extra strength.
Cut a mounting strip to fit the width and length of the bottom channel of the decorative handrail, mitering/angling the ends to fit the cap at the top of the railing and the horizontal section along the bottom.
Align the mounting strip below the chalk line. Drill pilot holes and then countersink holes for the screws on top of each stud
Use low-tack painter's tape to mask off the wall around the pre-stained mounting strip. Add some stain to the polyurethane and apply a second coat to match the existing stair railing. Remove the painter's tape.
Double-check measurements before cutting the expensive decorative handrail and the cut it to fit each section with appropriately mitered ends.
Slip the handrail channel over the mounting strip. Mark evenly-spaced screw positions on painter's tape along the railing that do not coincide with screws in the mounting strip. Countersink screw holes and drive in wood screws to secure the handrail.
Cut a short horizontal handrail for the bottom of the stairs, mitering one end to fit the angled main handrail and square-cutting the other end square to fit the wall. Secure it the same way as the main rail.
Cut a mitered cap of the same material to fit the upper end of the main handrail. Apply glue to the mitered surface and position the cap prior to driving in countersunk screws for extra strength.
Glue ready-made pegs of matching wood into the holes to cover the countersunk screws. Ensure the grain on the peg aligns with that on the handrail and gently tap them flush with the handrail using a hammer.