Hair extensions can be clip-on or glued in by a hairstylist. Clip-on hair extensions and lower-end salon extensions are usually synthetic, while high-end hair extensions are human hair. One problem with extensions that have been in for a while, especially if you have thick hair, is that your extensions may look thinner than the rest of your hair. Although human hair extensions are easier to style, it is possible to get your extensions to look as thick as your normal hair, whether they are made of synthetic or human hair.
Shampoo and condition your hair and extensions as usual. Pat dry gently with a towel.
Gently comb through your hair and extensions with a wide-toothed comb while spraying detangler.
Blow dry your hair until it is barely damp. Comb the front of your hair and extensions up in the air, and place three velcro rollers on the center of the top of your head, one behind the next, facing the back. Spray your head, including the rollers, with hairspray.
Continue blow drying your hair until it is completely dry. Take the rollers out of your hair and spray again with hairspray.
Using a hot curling iron, curl the ends of your hair extensions until their thickness matches the body at the top of your hair. Spray again to secure and scrunch lightly for extra body.