Measure the height and width of the wall with a tape measure to determine how much space you have to work with. Likewise, measure the cubbie sizes. Only measure up to the edge of the door in the room so a cubbie doesn't block the door from opening.
Place a row of cubbies near the bottom of the wall. Decide on a height that is most convenient for you to reach. Cubbies are often the same size but, if they vary, use larger ones on the bottom row and then smaller ones above it.
Position other cubbies on top of the lower ones so they are all touching each other. If you don't need to use that many, separate them so they're not clustered together on the wall for a more decorative appearance. For a larger number, they help support each other when their sides are touching.
Hang the cubbies near the top of the configuration slightly inward from the ones under them, to create a shelf space on the sides of the cubbies. These are useful for placing small photos and decorative items.