A huge couch in a small living room is hard to camouflage, so size your furniture pieces to suit the available area. For a space-friendly sofa, lose the extra stuffing and oversized arms and pick something more streamlined. Choose a smaller coffee table, or go for an ottoman and tray. Opt for a drop-leaf kitchen table or one with removable leaves that you can adapt to your changing needs.
Other ideas you'll like: Buy a narrow dresser that will fit out of sight in your closet. Employ shallow chests that hug walls and leave plenty of room to move around. Use nesting side tables in your living area for versatility and space savings.