I enjoy making “rough” but sturdy shelves. They go pretty quick, they don’t have to look great because generally they are for storage, and not in a sitting room.
First a 1×2 gets screwed to the wall horizontally, on studs.
Then, a shelf is screwed to that rail.
A front piece is glued and screwed to keep it from bowing too much.
Vertical pieces are screwed to the corners to level everything up.
