The first thing I did is I decided I wanted the island top to be 2'x4' so I cut pieces 22" for the top (the other 2" comes from the apron sides). I secured these together with 2"x 2" boards .
I cut pieces for the bottom shelf (this wood is reclaimed barnwood, mostly chestnut) and attached it to the bottom brace, except the middle shelf board.
I attached two 2"x 2" pieces to the middle board, screwing up from underneath the shelf board. I almost made a mistake here and put the 2'x 2" boards on the edge of the shelf board, but they need to be an inch in because this upright 2"x 2" board will be attached to the inside of the apron. THEN attach the middle shelf board to the bottom shelf bracket.
Secure the vertical 2"x 2" boards to the apron underneath. Next, I cut two 1"x 1" boards for a shelf bracket. I screwed one to the 2"x 2" boards and on to the legs (14" up from the bottom shelf). I then cut boards and added the middle shelf, using the nail gun to secure it to the shelf braces.
I sanded, and sanded, and sanded. (I am getting much better at wearing a mask while sanding!)
I added a tool box tray for a towel holder.