Remove the mattress. Lay a bed skirt, also known as a dust ruffle, over the box spring. The bed skirt should hang evenly over the foot of the bed and the two sides. Replace the mattress.
Cover the mattress with a fitted sheet. Pull the four corners of the fitted sheet over the four corners of the mattress and tuck them under the mattress. The elastic hem of the fitted sheet will hold it in place. If you have a mattress pad, put it over the mattress before putting on the fitted sheet.
Place a flat sheet over the fitted sheet. You can leave the edges of the flat sheet untucked or tuck the sides and bottom edge under the mattress.
Cover the fitted sheet with a comforter or bedspread. A bedspread will usually reach the floor, while a comforter reaches the bed skirt. Comforters are usually thicker than bedspreads, so select whichever one is best for the temperature in the room. A duvet is a covered comforter, so you can use that in place of a bedspread or a regular comforter.
Fold the flat sheet down over the top of the comforter or bedspread, if desired. Some flat sheets have decorative embroidery at the top edge, designed for display, but this is not necessary.
Place your covers on your pillows and put the pillows flat on the bed at the head, against the headboard or wall. You can put shammed pillows on top of these, vertically against the headboard, then prop decorative pillows against the shammed pillows.
Place a folded throw blanket on the foot of the bed for additional warmth, if necessary.