When the bedroom feels over-arranged, this kind of abstract helps. A silver half-moon sits behind fine horizontal lines on a deep charcoal grey ground, and the room gets quieter for it. Hang it above a low bed, a slim console or a writing desk where there's a bit of breathing space around it. It works with charcoal linen, pale oak or walnut, smoked glass and a chrome or matte black lamp. Keep the surrounding wall fairly clear so the moon shape can do its job. Avoid pairing it with very warm rustic timber, busy florals or saturated colour blocks - the calm gets lost. A black, silver or white frame keeps the look crisp.