I started by assembling and dry fitting all the pieces.  The two long middle pieces were 3/4" x 3/4" strips cut from a flat-sawn plank of aspen.  I rotate the 2 pieces 90° in opposite directions.  The yielded a vertical-grain stem with any bow in the wood counteracted by being glued back to back.  Next came a 5/16" strip of Cedar followed by another strip of aspen.