Three Tier Wooden Shelf/ Bathroom Storage Shelf

Required materials and tools:

2 x 4 at least 30" -1

2 x 10 at least 9"-1

2 x 10 at least 10"-1

2 x 10 at least 11"-1

(if you prefer equal tier length, buy three similar length  2 x 10s)
Sandpaper/sanding block (220 grit)-1

3" or 2.5" Wood screws- 9

Wood glue

Hand saw (or get it cut from the store)

Drill and drill bits

Measuring tape

Pencil

Paint or stain

Paint brush or foam brush

Tutorial:

1) Sand all the sides of wooden pieces to make the surface smooth. Wipe down entire surface to remove any dust from sanding. Lay out all four wood pieces.
The 2 x 4 (pronounced as 2 by 4) with 30" length is going to be the back support and the three 2 x 10s are for the shelves.  Decide the position of each tier and mark it with pencil on the back support.

2) Predrill screw holes. Predrilling screw holes guarantee that the screw won't break or the wood won't crack. Choose appropriate size drill bit (more precisely, a bit that matches the inner diameter of the screw thread). I used 1/8 drill bit for all my works.

 A total of 6 screw holes are required on back support, 2 for each tiers. Make 2 screw holes on the center of each tiers as shown below. 

drill with bit for screw hole

predrilled holes on back support and tiers

3) Place all tiers perpendicular with the side with screw holes on top. Apply generous amount of wood glue around the screw holes. Position the back support on top of the tiers so that the screw holes on the back support and tiers are well aligned.(You can use a thin wooden skewer or thin metal rod to check the screw hole alignment). Then, screw along the holes. For attaching three tiers on the back support, I used 6 screws, 2 for each tier.

4) The last step is to paint/stain the shelf. Allow at least an hour for the glue to dry before applying stain. Apply two coats of paint/stain and dry according to the directions.

(For staining I used Minwax polyshades-stain & polyurethane in 1step in expresso gloss finish. Unfortunately, I am not very satisfied with the result I got with this oil based stain on pine lumber. I can see blotching as pine is a soft wood. It needed 2 coats of stain at least to get satisfactory results. Next time I would select a water based stain. Brush cleaning procedure is much more easy with a water based stain. Whereas for oil based stain, mineral spirit was required to clean up the brush.)

5) For mounting the shelf on the wall, make three equidistant predrilled screw holes on the back support and screw onto the wall.