My wife wanted some shelving in the half bath. Didn't like what was commercially available, so I hit the garage and using some scrap wood, I put these together.

Step 1: Making the Shelves

While I'm certain there are better and more decorative ways to assemble these, this is the method I used. 2 equal pieces for top and bottom. 1 long piece for the front. A ripped down strip to fill the sides and for the back.

I used more of the side/back material to create fingers for additional strength and assist with alignment. The fingers were screwed in from the back with wood screws, pilot holes drilled to prevent splitting the thin material. You can see the second shelf being test fitted for the base, discussed further later.

Step 2: Mounting the Base to the Wall

I marked the studs on the wall, positioned the base where I wanted the shelf to rest, and marked places to drill pilot holes. Anchor 1 side, then use the level to ensure its straight while I anchor the other stud.

Step 3: Afix the Shelf

The shelf is really just a long thin box. I used finishing nails to help hide the fasteners with a little wood glue and saw dust. Slide the box/shelf over the attached frame until flush with the wall. Test fitting the base before this step is helpful to ensure a good snug fit without excess or the fingers being too long. Then I attached the shelf at the back on the bottom (for the lower shelf) and top (for the upper shelf) with screws to help ensure they are not seen.

Step 4: Finishing Touches

I had sanded the pieces before attaching to the wall. I finished them with some beeswax mixture I purchased to keep a natural look. I had wood left over so I attached a small piece to the wall with L brackets to hold the toilet paper holder to tie it together.

Spent maybe an hour putting these together, and while they are not masterpiece level, my wife loves them.