Daybeds range in styles and mattress-type offerings, but most are twin-sized and come with a frame and headboard. The lower bed commonly pulls or rolls outward and remains at a lower position for the second sleeper. Sometimes a daybed is broader than the average twin, or it lacks the secondary accommodation. Some people use a daybed in place of a sofa. It shares some similarities with the futon, which can also double as a couch and a bed.
Some manufacturers of daybeds also offer full sets of bedding to accompany their products. The basic sets include a fitted bottom sheet, a flat top sheet and pillowcases. Full sets can also include mattress covers, bed skirts, pillow shams, comforters and other accessories --- all in the same pattern or color scheme. While these are quite handy and are often visually appealing, choose what your budget will allow, as prices vary considerably.
You can find alternative bedding if you search for sales and quality materials. Fitted sheets sized to the daybed, such as for a standard twin, will work just fine. Look for high thread count deals on sets of twin sheets. Mix and match fitted and flat sheets using, for example, green with blue, purples with pinks or variations on stripes and solids. You can also use larger-sized sheet sets, though you'll have to snugly tuck in the extra fabric. Accessorize with brightly colored, patterned throw pillows and bolsters. Add a solid-color bed skirt if you want to hide what's beneath the top-level bed. Feel free to experiment.
Some people have regular guests and will leave at least the upper portion of the daybed made up. If it's a single anyway, the point is moot as to whether you need to prepare a lower sleeping arrangement. However, when there are two beds to make, you can choose between leaving the lower bed made up or not. Ideally, fresh sheets should be added just before a guest arrives. Add other touches to decorate the bed and the room to make your guests feel welcome.