For a wall shelf, the best place to start is at the beginning – the wall.
How will the shelf be mounted to the wall?
Perhaps the biggest challenge in designing a successful wall shelf is attaching it to the wall strongly enough to support it and whatever it supports. The method of attachment will in part dictate the design of the shelf. Consider these methods of attachment when designing your shelf.
Angle Brackets and Screws
Probably the simplest attachment method involves store-bought metal brackets and screws to attach the shelf to the wall. This method is simple and effective, but hardly elegant. To improve the look, use fancier metal brackets or make your own corbels from wood, metal, or another material. Screws can be visible or hidden. If you want to anchor the brackets into studs, you will have to consider that in your design and mount them accordingly.
If your shelf has a structural back, you can screw directly through it into the wall. It’s typically not very discreet, but with the right design and right choice of fastener it can look very good. In this case, as soon as books are loaded on the shelf, the back plate and screws are hidden.
A special keyhole-shaped slot that is wider at the bottom and narrower at the top captures a screw head to hang an object. The keyhole mount is mortised into the back of the piece and not visible from the front or edges. Cut keyhole slots with a special router bit, or buy metal keyhole brackets that attach with screws. These require a degree of precision to install, and may dictate where the shelf hangs on the wall if you need to hit a stud.
A versatile and strong method of hanging something, a French cleat is usually invisible once the shelf is installed. A wide cleat provides a good chance of being able to hang it where you want and secure it to at least one stud. Comprised of a pair of matching strips with mating chamfers on the edges (usually 45 degrees), one is mounted to the wall and the other to the back of the shelf. You can hide it in a recess in the back of the shelf to make it invisible. The cleat allows simple drop on/lift off installation.
Variations of this exist, including the narrow cleats I use on my tusk tenon wall shelves, and low-profile manufactured metal cleats.
Slide-On Floating Shelf Systems
This style of mount consists of one part that fastens directly to the wall, and the shelf slides right over it for installation. Shop-made versions typically involve a strip of wood or wooden frame screwed to studs, and a hollow shelf that slips on and covers it completely. Like a wide French cleat, a wide mount makes it easy to fasten to the wall wherever you like.
Metal hardware exists too, which typically requires two or more deep holes cut into the back edge of the shelf. These holes can be drilled, or routed in if the shelf is laminated. If the hardware must be mounted to a stud, this style of hardware makes it more difficult to mount it exactly where you want.
Need More Ideas?
If you need some more ideas, try wandering the aisles of your local hardware or home decor store. You can also check out my Wall Shelf Build-Off Pinterest board, and remember to register for the #WSBO!