keep exact same room geometry layout grey curtains silver grey carpet dark grey walls led strip lighting under bunk and shelves amber cushions and dark bedding only change the shelf accessories to suit a 12 year old boy s bedroom add items such as a football sports trophies action figures a small gaming controller comic books a lego model a small speaker a skateboard leaning against the shelves sports posters or pennants a torch a nerf gun on a shelf make it feel like an exciting cool boy s bedroom