I'm working on building some master closets in a complete tear down. I.E. hardwood floor guys have come in and installed floors, but the baseboards and everything were removed. We reinstalled baseboards in the main areas, but not the closets as we were still working on the overall finish.

I have 84" 18" 12" cubbies which i made out of MDF and cut out notches in the long boards for the shelves. I'm attempting to make them as thin as possible so i'll putty the front edges to give them a finished look. The goal being to put them in the center of a 6 foot closet with closet rods on either end to give it a built in finished closet look that is flush to the wall. I've finished cutting everything, but now i'm sitting here wondering what the best way to mount them is.

I'm thinking I could cut a board similar to the baseboards and attach it to the inside of the cubbies at the base maybe a 1x3 and attach that to the studs. I also have some 3/4 dowel squares I could attach to the shelving at unseen levels i.e. floor level and above eye level and countersink a bit to attach them to to the studs. When I used the stud finder I only found one stud behind where the mid section of the cubbies in the closet would be to attach either item. I could use an anchor as well if necessary, but I'm open to ideas.