The formula: 5 + 3 + 1
Five seats, three surfaces and one light source. A curved sofa plus two accent chairs seats five comfortably; a coffee table and two side tables give everyone somewhere to set a glass; a floor lamp or cluster of candles makes the corner glow after dark.
Face chairs inward
It sounds obvious, yet so many lounges face the room like an audience. Angle every seat toward a shared centre point and strangers start talking within minutes.
Anchor with a rug
A rug turns scattered furniture into a room. Size it so at least the front legs of every seat sit on it — anything smaller looks like an afterthought.