If you are personally cutting this at home, cut your lumber for ONE CLOSET SHELF to make sure your measurements were right. If they were great then it’s time to cut the lumber for all remaining shelves.
Make sure it is level as this is how you will support your closet shelf, and remember your shelf is 1 inch tall and will sit ON TOP of this, so if that matters in terms of your placement be aware. Use your drill to attach this piece – if possible putting into the studs.
Same height and push them as far back and close to the back piece as you can. It’s fine if there are gaps, but the biggest thing to remember is it can’t hang in front of your top board. Use your drill to attach these to the walls .