Decorate only with items you will need. Don't bring additional furnishings in to the room that is only gonna cause clutter. You will need to feel comfortable in your bedroom and part of the sense is knowing you have enough room to go.
Place smaller furniture resistant to the shorter walls if this works. You might consider putting a tall dresser against a brief wall, with a bureau‐style dresser resistant to the long wall opposite the bed. If possible, use under‐bed storage rather than one of the dressers.
Determine whether you wanna hang pictures on the walls. In a tiny bedroom, pictures can make the area feel smaller, so do that sparingly.