What I used , 1x3x97 " pieces of wood , and hardwood dowels.
I simply cut the pieces to the length I wanted , drilled matching holes on the sides of the boards and inserted dowels , hammered the boards together , and since they were really tight that was enough to keep everything together , no glue , but glue can be used . I then decided on the diamond pattern , measure the half way point on each side voila there is a perfect diamond . I then measured the trim pieces and cut the angles by hand , I clamped the pieces to my table to make that difficult task easier . Attached the trim with glue and nails , sanded filled any gaps with filler , painted , and installed . That is it .