Common mistakes with bedroom alcoves include choosing elements too deep or too shallow, poor lighting, and trying to fit too many functions into the small space. For example, shelving deeper than twelve inches overwhelms the nook, while insufficient lighting makes it feel cramped. Also, combining a vanity, closet, and reading nook all at once creates cluttered, confusing spaces. Focus on one primary use per alcove, use proper dimensions like ten to twenty-four inch depths, and install warm, well-placed lighting to ensure the space feels intentional and functional.