Measure the distance between the vertical and horizontal beams that the bracket will span.
Use this measurement to cut two pieces from the 2-by-4 stud.
Measure the distance diagonally of the open side of the "L" bracket. Cut a piece of the two-by-four long enough to span this opening. Take your T-square and mark a 45-degree angle at the ends of this piece. Cut the ends of this piece at 45 degrees with the table saw. The flat portion of the angle cut will face outwards, towards the straight-cut pieces.
Add decorative touches as desired, using the router on the edges of each piece and the scroll saw for more intricate designs. Wood stock is cheap, so practice until you've found a nice design.
Set the two straight cut pieces into an "L" configuration. Drill two holes into the junction point of the "L." Drive two 2-inch galvanized Philips screws into the holes.
Drill and screw the 45-degree cross member at the hypotenuse of the "L," forming the bracket.
Paint or stain the bracket prior to installation. Allow the proper amount of curing time, as directed by the manufacturer.
Pre-drill two holes on the inside facing edges along the top and back of the "L" bracket. Attach the bracket to the pergola with 2-inch wood screws, meeting the outside corner of the bracket to the meeting join of the vertical and horizontal beams.