Take stock of what is to be stored on the wall unit. This is an efficient way to determine which items you want to be on open display and which ones you need to hide behind cabinet doors. Wall units are not only decorative; they also put within reach items that are frequently used in the space, without the need to store them in a nearby closet.
Measure the width and height of the items designated for storage on the wall unit. These measurements make it easier to determine the minimum amount of shelf storage space the wall unit must have.
Incorporate open shelves and closed-door cabinets into the design of your wall unit. If your wall unit is flanking a fireplace or another focal point on both sides, balance the amount of shelving on both units. The amount of books and decorative accents will help you determine the number of shelves you need, and the equipment and other items that are best concealed will determine how many closed cabinets and drawers your wall unit must have.
Research design styles for wall units. Find the one, or ones, that answer the layout plan of your wall unit. You may find that cabinets are best placed near the bottom of the unit with open shelves on top, or that the cabinetry serves its function better at the middle or near the top of the unit. Balance the wall unit's design by repeating its layout on the other units, if your wall units have two or more sections.
Select the decorative accent features and finishes for the wall unit. Help the wall unit blend into the room with crown molding that continues onto the ceiling, or dress it up with other trim molding and hardware tones that are consistent with design elements already in the room.
Plan the finish of your wall unit. Decide if it will receive a stained and polyurethane wood-tone finish, or if you are painting the unit to blend in, or accent the wall and trim colors.
Hire a professional carpenter to construct the wall unit, unless you are one yourself. After all the planning, selections and measurements, the carpenter can translate your drawings and ideas into a wall unit custom designed for your living space.