For lumber storage in my shop, I like to stand boards on end. That makes it easier to sort through the lumber to find the board I want. It also lets me separate boards by wood species.
To keep boards organized (and to prevent them from falling sideways), I made a simple lumber rack from some lengths of black-iron pipe and a few plumbing fittings (Photo, below).
I used 3/4″ pipe for this rack, which is available at most hardware stores. For a small price, you can have the pipe cut to whatever length you want (24″ in my case). You’ll also want to have threads cut on both ends of each pipe. One end threads into a pipe flange that’s screwed to the wall. The other end gets a cap.
Have a nice weekend,