Use pillows generously
Pile on the pillows, combining large prints with small ones, florals with geometrics.
That big blank wall can be made to disappear by hanging a graphic quilt or painting on it. Complementary bed covers will bring harmony to the decor.
Use the walls
Space can be a pain in the you know where, especially a lack of it. Affixing lamps and other fittings to it can reduce visible clutter as well as being functionally aesthetic