Summarize the following:
Choose a sweatshirt and sweatpants of the appropriate size for the costume wearer. You can go with white for a fully white sheep or a black sweatsuit for a black sheep. Choose a hooded sweatshirt for one version of the costume or a crew neck if you want to have a separate hat or headband.  If you think you’ll be too hot in a sweatsuit, you could go with a long sleeve shirt instead. Sweatpants are probably your best option for pants unless you want to choose some tights, leggings, or other simple black or white pants. If you use clothes you already have rather than buying new ones for the costume, remember that you’ll be using glue that is permanent. Once you make the costume, the clothes are ruined for regular wear. For a small child’s costume, you can use cotton balls because you won’t be covering a large area. If the costume is for an adult, you’ll want to use some kind of synthetic cotton or polyfill batting because it will attach more quickly, and cover more area, than cotton balls. You can use polyfill for a child’s costume, as well.  Cotton balls can be purchased at any big-box store or pharmacy. Batting can be purchased at big-box stores, but you might have to go to a craft store. Cotton balls give a more textured and authentic look, but cotton batting will attach much faster and cover more space. If you are in a hurry, don’t use cotton balls. It won’t be easy to wash the costume once it is fully assembled, so wash everything now if you want to. It is especially good to wash brand new clothes to break them in a little and make them more comfortable. It is not necessary to wash clothes that you’ve worn many times if they are clean already. Using hot glue or fabric glue, begin attaching the cotton to the shirt and pants. Bunch the cotton batting up as you glue it, so it looks like sheep's wool. Place the cotton balls close together so there aren’t gaps. You don’t have to cover the entire surface of the clothes with cotton. You can leave a few inches at the end of the sleeves and pant legs to mimic the way that a sheep’s wool stops before the hooves.

Summary:
Select a black or white sweatsuit. Choose cotton balls or polyfill. Wash the clothes. Glue cotton batting or cotton balls to the clothes.