The ancient Egyptians dressed for their climate in lightweight linen. Their clothing was minimal, even non-existent or a mere loincloth for most slaves, and they generally went barefoot. For the wealthy, clothing was often sheer and usually pleated in narrow vertical folds. Wealthy Egyptians wore elaborate jewellery, wigs and make-up and all Egyptians---male and female alike--were especially fond of kohl, a black, soot-like eyeliner. You should study ancient pictures for a truly authentic costume.
The Egyptian Mummy
Start by donning a white unitard or white tights and T-shirt. Use white cotton gloves and socks to cover hands and feet, and if you have one, a white silk pullover stocking cap/mask for your head. Tear a plain white sheet into wide strips. Have a friend wrap the strips around your body, spiral fashion, overlapping the ends several times to hold them without pins. Tie strips off here and there and let the ragged ends dangle slightly for a realistic-looking mummy.
Start with an ankle-length, sleeveless, loose white, tunic--preferably pleated. Tie a rectangle, pleated horizontally, around the shoulders as a shawl and knot in front just below the breasts. You can make this from a thin sheet with 1/2-inch pleats ironed in. For jewellery add a breast plate made from poster board painted to resemble the red coral and blue lapis lazuli stones set in gold prized by ancient Egyptians. Wear a straight, shoulder-length black wig and tie on a headband of striped cloth. Attach a gold spray-painted plastic snake's head in the front to finish.
Male Egyptian Worker or Slave
Most Egyptian slaves went naked or wore simple loincloths of white linen. For a man's loincloth, start with a rectangle of white cloth or faux leather. Cut one end of the cloth wider than the other. Sew two long ribbons to it--one on each back corner. Tie the wider portion around the waist from the back for a belt. Pull the front of the cloth between the legs and up through the belt from underneath, allowing a portion of the cloth to hang down in front. Archaeology offers advise on slitting the cloth for achieving a more authentic look, if you have a lot of time on your hands. Tie a red and white striped sash around the waist to hang on one side. Wear a ribbon headband of white or red over a short black wig.
Female Egyptian Worker or Slave
Female workers and many female slaves wore a topless, close-fitting tunic of white linen, sometimes with wide shoulder straps. Make a straight white tube by sewing together the ends of a rectangle of stretchy material such as a white T-shirt. It should fit tightly from just below the breasts to mid-calf. Sew on two wide straps to stretch front to back over the shoulders to cover the breasts. Use the same style head gear as for male slaves. Simple flip-flop style leather look sandals are optional.