Cut the foot pieces to size and stack 2 pieces together with 2" brad nails and wood glue. Build 2 foot assemblies.
Cut the footboard trim to size and drill 1 1/2" pocket holes at both ends. Attach it to the feet with 2 1/2" pocket hole screws and wood glue. The front and top of the trim should be flush with the front and top of the feet.
Cut the footboard rail to size and drill 1 1/2" pocket holes along one edge and both ends. Attach it to the trim and feet with 2 1/2" pocket hole screws and wood glue. The back of the rail should be flush with the back of the trim.
Cut the side trim pieces to size and drill 1 1/2" pocket holes at both ends. Attach the trim to the foot with 2 1/2" pocket hole screws and wood glue. Do this for both sides of the bed frame.
Cut the side rails to size and drill 1 1/2" pocket hole screws along one edge and both ends. Attach the rails to the trim and feet with 2 1/2" pocket hole screws and wood glue. The back of the rail should be flush with the back of the trim and inside of the feet.