Start by cutting your 1x12" board and 2x6" board to a length of 24". Then, cut each 2x4" piece to a length of 11.5". Sand each piece of wood once you have them cut to length. I used 100 grit sand paper with a random orbital sander, but any old sand paper should do the trick.
DIY Floating Shelf
Simple yet versatile DIY floating shelf that looks great anywhere in the house. I've used these as spice racks, bathroom organizers, and entry way shelves.
24" X 12"
Put wood glue on one edge of your 2x6" and align it evenly at the bottom of your 1x12". Nail or screw it in place from the backside. A nail gun works great for this step.
Next, take one of your 2x4" pieces, put glue on one of the edges, and place it on one of the top corners of your 1x12". Nail or screw it in place from the backside.
Then, measure 3" from the top of your 1x12" and draw a horizontal line marking your measurement. This is where you will be placing your second 2x4" piece.
Put glue on one edge of your 2x4" and place the top of it in line with the line you drew at 3" from the top of your 1x12" board. Nail or screw it in place from the backside.
Add stain or paint if you'd like and let dry over night. Once it's dry, add polyurethane or another finishing oil if you want a shinier look.
On the back of your shelf, take two key hole hangers, make sure they are level, and screw them in. For my shelf, I placed them 3" down from the top of the shelf, and 4" from each side of the shelf.
Use a drill bit that will fit inside your keyhole hanger to carve out the wood so you can hang your shelf. Make sure not to drill all the way through to the other side! A 1/4" should be fine.
Your shelf should now be ready to hang!
Add an optional bar to the bottom of your 2x6" if you would like to hang towels or kitchen utensils. I used an 18" bar that I had laying around from IKEA.