Wanted a little spot for my daughter to place some of her hair accessories and other misc things she wants to display. I used a piece of leftover 1x12 I believe it was. I cut them on an angle on the miter saw... so they were triangles. I cut pocket holes on the underneath side and also on the fronts to add a piece of trim... which I think I use a 1x2... measured and cut the edges to fit flush with the wall. I measured from the floor and spaced all 4 of the shelves evenly. My goal was to screw directly to the wall studs... I think one side had a stud... plus the corner itself... the other side was just to drywall, but they are not very big and after doing 1 knew these babies were secure, I primed and sanded before mounting... then after mounting.... I filled any gaps with caulk and then painted them in a whit semi gloss to match the rest of the room.
This is a corner of the room that would otherwise have been unused. The closet door opens to it and the big window is next to it. So I felt confident the shelves would never be in the way of furniture if I rearranged the room