Step 1: Cut the Wood

Tip - I marked the pieces with their lengths just to make it faster when assembling.

Cut one 2X4 into two 35 inch pieces and a 21" piece. 

Cut the second 2X4 into two 15" pieces and three 21" pieces.

Cut one 1X4 into a 52 1/2" piece, two 16 1/4" pieces and one 10" piece.

Cut the second 1X4 into a 52 1/2" piece, a 30" piece and a 10" piece.

Cut the third 1X4 into a 30" piece, two 9" pieces and two 18" pieces.

Cut the forth 1X4 into four 18" pieces