A homemade nun costume is easy to make as long as you start with a simple black garment, which greatly reduces the amount of sewing necessary for this project. Once you have chosen an appropriate garment, it is simply a matter of adding the appropriate accessories to transform your clothing into a nun costume. You can also create a racy nun costume by choosing a shorter dress.
Purchase a simple floor-length, long-sleeved black dress, a black choir robe or a black graduation robe to serve as the base of your costume. This will eliminate the need to sew a garment, which can be difficult and frustrating if you are not familiar with garment construction.
Measure around your head at approximately the centre of your forehead.
Cut a rectangle of black fabric that is your head measurement plus 2.5 cm (an inch) by approximately 75 cm (30 inches). This fabric will become the headpiece of your nun costume.
Cut a rectangle of white fabric that's your head measurement plus 2.5 cm (an inch) by 7.5 cm (3 inches).
Lay the white fabric on top of the black fabric with right sides together and the edges that are equal to your head measurement plus 2.5 cm (an inch) lined up. Sew a seam along the edge using a 1.25 cm (1/2-inch) allowance.
Unfold the fabric so that the right sides of both fabrics are facing up. Iron the headpiece to flatten the seam you have created.
Fold the entire headpiece with right sides together. The ends of the white fabric should match up.
Sew the sides of the headpiece opposite the fold together using a 6 mm (1/4-inch) allowance. Turn the headpiece right-side out, and you will now have a long tube of fabric.
Place the white end of the tube on your forehead like a sweatband, and allow the black fabric to drape over your head and down your back.
Cut a 60 cm (24 inch) diameter circle from white fabric. This will create the white collar for your nun costume.
Cut a 17.5 cm (7-inch) diameter in the centre of the white fabric circle. Place the circle over your head to wear the collar on top of your black dress. If you cannot easily slip it over your head, cut the hole slightly larger until you can.
Wear a rosary or a large cross around your neck to complete your nun costume.