On a table saw, cut the stock to the appropriate size. Next, cut a chamfer on the edge of the wood to give it a finished look. To cut the chamfer, first set the blade angle to 45 degrees and cut a sliver of wood from the edge. Be sure to use a common throat plate, as it may not be possible to use an untethered clearance throat. Add chamfers to as many edges as needed.
On a router table, cut a groove the size of the bar in the wood, using a bit that corresponds to the size of the bar. Use a feather board on the router table to brace the wood against the fence for the most precise and clean cut possible.
Before putting the aluminum bar in place in the groove, use a random orbit sander to polish it first. Use a high grit sandpaper to achieve a shiny finish. Placing a rubber pad under the bar will keep it from moving while sanding. Place the stock bar in the slot. A rubber mallet may be needed to tap it into place.
Use contact adhesive, white glue, or screws to hold the bar in place. If the aluminum bar is screwed to wood, first cut the screw clearance holes in the bar with a drill. Use a bit to countersink the screws.
