The idea here is to create a wall mounted 'ladder' of sorts to store shoes. I've built things like this before - one is a great Instructable called a Shoe Tower. But I recently moved into a new place and needed to create something that is next to the front door, but doesn't take up too much space.

Materials:

Vertical supports - I used Redwood 2x2 from the local big box store that are intended for decking railings. The 1.5 inch thickness is just enough to sneak in the sneaker toes; but not so deep to take up floor space; and
Horizontal slats - these don't need to be super strong, but not so flimsy they will break under the weight of shoes. I ended up with some sections of molding (3/8 inches thick, 1 inch high), normally used for floor molding, but again, I just needed something straight (ish) and strong enough; and
Mounting hardware - the vertical supports are screwed in with 3 inch wood screws (tight threads) and the horizontal slats are secured with small brass brads.

Tools:

Measuring Tape, Level, pencils
Drill, counter-sing drill bit, hammer (or stapler if you opt for that route; see note in Installation of horizontal slats)
OPTIONAL: Stapler.

Other Resources:

Time (after sketching it out and thinking it through, this is quick): about an hour
Cleaning supplies - I had crudely piled the shoes for several weeks, so lots of dirt and other things had ended up around the area.

Step 1: Prepare Vertical Supports

Long ago, I learned the virtue of the well measured pre-drilled screw hole. No splitting, no over exerted force, no regrets.

My vertical supports are three feet long, so I pre-drilled (with a counter-sink drill bit) a hole at the top, middle and bottom of each support. I decided to go with the counter-sink for several reasons. The first was aesthetics, and the second was practical. The horizontal slats will be placed at various heights and I didn't want to over plan and try to avoid a horizontal slat going over a screw. This way, the slats can land anywhere.

NOTE: If you wanted to stain, paint, decoupage or in any way adorn your shoe rack - now would be the time to do so. I didn't want to (most of my place is wood in raw form).

Step 2: Installing Vertical Supports

For each support, I started with the middle hole, then lined each up square to the world. I started with the right support (in the corner of my entry way), then left, then measured the center point between the two. I was a little concerned that my walls were not totally straight, but they turned out to be.

I took a final measurement from the outside of the left vertical support to the outside of the right vertical support so I would know how long each horizontal slat needed to be. These vertical supports are rounded at the edges, so the measurement is a bit off - and the right side of each horizontal slat will run into the wall, so the measurement is rough only.

Step 3: Preparing for Horizontal Slats

The first step is to install the lowest horizontal slat. It needs to be flush with the bottom of the vertical supports. I ended up getting three 9 foot lengths of my horizontal slats, so the first was a bit of a trick to line up to measure. But I found it best to measure each slat on site and then cut.

Alternatively, you could take the engineer/math-is-great route and measure, then cut all slats at once. Or take a step further into obsession with exactness and set up a fence on a chop saw to ensure absolute uniformity. But I majored in Philosophy with a focus on existentialism and fundamentally don't believe in absolute uniformity. Even amongst thin pine boards.

But, to each his/her/their own.

After each cut, it is worth running over the edges (especially the cut edges) with some sandpaper. Your shoes are going to slide in and out of these and a smooth edge will make that a bit easier and not give your shoe splinters.

Step 4: Installing the Horizontal Slats

After each slat is cut, I nail it into the center support, then ensure it is level and nail into the other two. Grab a pair of shoes and place on the slat. Then bring in the next length of slat material and roughly place over the toes of the shoes, just above enough to get a grip, but high enough to make it simple to get the shoes in and out.

Here, gravity is the unseen helper. The shoes should go in just far enough to create a fulcrum with the horizontal slat, then 'drop' down by the weight of the rest of the shoes and thus press up against the next horizontal slat.

This is where I am glad I switched to nails as this may take a bit of adjustment. Also, it is good to put like thickness shoes together.

Lastly, I decided to keep heavier shoes (hiking boots, motorcycle boots, etc.) on the bottom and lighter (sandals) towards the top. Again, Newton had it right and things are proportionally attracted to the center of the Earth. Meaning the heavier the object, the stronger the desire to be closer to the ground. And, it kind of makes sense from an organizational point of view. But again, to each her/his/their own.

Repeat each row accordingly - taking all the shoes out each time. I know, I know, tedious, but hey, I had some time and enough Virgo in me to do this somewhat systematically.

Step 5: Top Row / Finishing

Once you get near the top, you may find you have odd spacing. I did.

I noticed that some lighter shoes with thicker toes actually needed more space than heavier shoes with thinner toes. For those rows, I went to a larger gap, each time trying to make it just wide enough to hold the shoe and not let it drop too much. There were lots of adjustments (removing and replacing a row).

For that last few rows, I knew I would have at least one really small row, so I left it open. I'm going to let it set for a few weeks and see if the choice of thin slats was the right one. If any break or splinter, I will re-do with thicker slats. The trick with the ladder style rack linked in the introduction allowed for shoes to be inserted as far as they needed. Here, Space is a premium, so I may need stronger slats to hold up the shoes.

For the topper, I picked up some corner finishing (also pine) and nailed it into the top. Upon further reflection when I was done, I think I want to paint this, but not sure, so I am leaving it raw for the time being.