For silky, soft, fine curls or hair with loose curls or waves, use a hair diffuser to remove much of the moisture from hair. The warmth helps fine hair hold its shape longer. Water in hair (and moisture in styling products) weighs hair down and pulls out the waves. Use products with glycerin or a heat-protectant to prevent damage.
Use a Hair Diffuser to Boost Fine Hair and Wavy Curls
How to use heat to set the waves and curls in fine hair.