To make a small bedroom with sharp angles appear more roomy and comfortable, think carefully about the paint colors you use on the ceiling and walls. Minimize the sharpness of the angles by painting all slopes and angles the same color as the walls. Only the flat parts of the ceiling should be a different color. Opt for white or another light shade for the ceiling to create the illusion of height. A dark ceiling will only make the space seem more cramped. If you have a very small area of ceiling, consider painting the ceiling the same color as the walls, but make sure it is a light color.
Keeping furniture to a minimum will make your small bedroom look larger, but of course that is not always practical. Look for pieces of furniture with multiple uses, such as a bed with storage underneath. Choose a few small items instead of large pieces that are likely to look too big for the space. Make the most of the small space at a dormer window with a small bench or desk and chair. Place taller items against walls with the most height, but make sure you leave some wall space free to avoid drawing attention to the angled sections.
Well-placed lighting will make your room appear bigger. The more natural light you can get into the room, the better. Choose lightweight or sheer drapes rather than thick, heavy window treatments. To avoid taking up valuable floor space with lamps, install wall lighting. If possible, hang a mirror on the wall opposite the window to reflect light and create the illusion of more space.
Like furniture, too many accessories makes a room seem smaller, so keep clutter to a minimum. Hang one large print on the wall instead of lots of small ones, which will create a focal point and draw attention away from the sharp angles of the walls. Introducing round shapes into the room with rugs and cushions will have the same effect. Don't be scared to bring darker or bolder colors into the space with bedding and other accessories, as these will contrast with the lighter walls and ceiling and create another distraction from the angles.