We had not used the clothing closet at all so far so we decided to change it into shelves.
each shelf is 12 inches in height.
I used metal shelving brackets cut to length from Home Depot
then I cut the shelving material the exact size of the interior box. 1/2 pine
I then dremeled out a notch in each corner of the new shelf to be able to have the vertical bracket slide up the side of the box without actually being attached but to still fit snug in the closet.