Basic thermal underwear serves as the base for this spectacularly spooky mummy costume.
Prewash muslin. Mix dye -- 2 cups water, 2 cups coffee, and 1/4 teaspoon black paint -- in a large bowl. Submerge muslin in dye for 10 seconds; wring thoroughly. Allow muslin to air-dry (if line-drying indoors, protect floor beneath with paper towels).
Notch muslin with scissors every 2 inches along one side. Tear at each notch to create 2-inch strips.
Begin with thermal underwear as base for costume. Slip a spray sock over head.
Apply dark makeup around eyes and mouth with a sponge applicator.
Attach a strip of dyed muslin to spray sock with a small safety pin and wrap around head, leaving eyes and mouth exposed. Repeat until head and neck are covered.
Attach and wrap muslin strips to thermal underwear, and wrap body as you did head and neck.