A daybed is wider than a couch, so it is best used in a room big enough to accommodate the larger frame. You can place it against a wall or in the middle of the room, but it looks less like a sofa and more like a bed if you position it in a corner or a large room. End tables at each side and a coffee table in the front of the daybed turn it into seating.
Daybeds require a lot of padding and pillows to provide enough support for sitting and leaning. Firm foam pads covered in fabric and placed against the back of the frame make the daybed look more like a couch. Body pillows with zippered covers also work for this purpose. A layer of smaller, decorative pillows placed in front of the foam pads provides depth and comfort.
Cover the mattress with a liner, sheets and a decorative blanket. Full- or queen-sized blankets are long enough to tuck beneath the mattress, and the extra material will camouflage the mattress fabric and cover the sheets. Sturdy fabrics are more stain-resistant, will stay in place better than a thin coverlet or quilt and resemble traditional sofa fabrics.
Making the bed with complementary sheets and pillows adds polish to a makeshift sofa, but coordinating drapes, accessories and upholstery extends the theme throughout the room. Simple, modern elements can accent daybed frames of the same style, and eclectic accessories tie a vintage or distressed frame with the rest of the decor.