Start On A Wet Canvas
When your hair is wet, it's much more pliable and easier to styling. Applying heat to wet hair causes the hair to stretch and conform to the brush or your fingers, which is a surefire way of gaining volume. When heat is applied to dry hair (like with a curling iron, flatiron, or other tools), the hair cuticle compresses, and the hair can actually lose volume — hence my recommendation to begin with wet hair.
Develop A Sound Blowdrying Technique
Getting the slight bend at your hair’s root area can create waves of gorgeous volume. Using a round brush with the blowdryer set to medium heat, smooth your ends and wrap the hair cleanly around the brush. Rolling the brush all the way to your scalp, let it cool momentarily. Once cooled, unroll your brush. The hair will have conformed to the shape of the brush, thereby giving you a tremendous boost in volume.
Learn To Use Styling Tools Effectively
Once your hair is dry, there are some heat tools that will aid tremendously in volume creation. Using the R-Sessions Root comb, a small rod with teeth which heats up very quickly and can be pressed on your scalp without burning you, is extremely effective. Use it to comb your roots in an upward direction to boost volume.