Measure allowable floor space and wall space for the desk. Sketch the room's floor plan on graph paper to figure out a traffic pattern. Plan to attach a writing shelf about 18 inches wide, if floor space is cramped. Move a chair to the make-shift desk on an as-needed basis. Carve out room for a full desk and chair if you have room.
Keep the desk style in harmony with the furniture. Use a sleek wooden desk without bulky side drawers, if the bed is streamlined with a simple headboard. Plan to buy an antique desk in oak or walnut, if the bed and dresser are antiques. Match the desk to the furniture -- not the other way around.
Create the desk for the proper height. Buying the perfect size desk is the best option. However, you can use a 2-inch sheet of plywood to raise a desk surface, covering the plywood with wood veneer. Make sure you feel comfortable working on a laptop or writing at the desk at a specific height to avoid back problems. Avoid trimming legs of a desk, because this is very difficult to do accurately. Replace all four legs instead, if needed, with premade legs in a shorter size.
Include a system for clutter control. A bedroom desk will collect much paperwork over time. Buy a small file cabinet or choose a desk with three or four side drawers to hold items. Use a file cabinet in a nearby space if you don't want drawers or storage with the bedroom desk.
Remove bedroom furniture or reduce its size if the room looks crowded. Move a chest of drawers to a large closet, for example, or place a bedroom chair in a hallway alcove to free up floor space in the bedroom. Consider substituting a smaller sized bed to shave a few inches off the floor space used.