Since an office desk is a functional piece of furniture, its design should reflect its intended uses. If your desk will be used primarily for a computer, then design enclosures and shelves for the computer's various components, including the CPU, monitor, speakers, printer, and keyboard and mouse. Depending on the size of the room, add storage to your desk. This can include spaces to store additional computer components like a modem or router, CDs and DVDs, and external drives. Storage for general office supplies can also be useful.
Measure the room where the desk will sit, or measure an existing desk if your new desk will serve as a replacement. Also take measurements of your computer and other items you plan to store in the desk. Another important measurement is the height of your desk chair. Measure from the floor to the level at which your arms rest when seated. This is how much space should be allowed below the desk so that you can work comfortably. Visiting a furniture gallery or looking at pictures of desks may help with design ideas.
Wood is the best material for a homemade office desk. A plywood desk can offer an inexpensive solution, but woods such as pine or oak will make a much more beautiful, durable desk. Choose lumber that is free from blemishes and has an attractive grain pattern.