You're not caring for your scalp.
It seems obvious that healthy hair starts at the scalp, but so many of us are overlooking its health in favor of convenience. Dry shampoo may be a time saver, but using it too frequently can irritate your scalp, clog the hair follicles, and eventually lead to hair loss. (Learn more about dry-shampoo-induced hair loss here.)
Instead, reduce your use of dry shampoo to a max of two days in a row and wash your hair regularly with a shampoo that maintains your scalp's pH levels, such as Harklinikken's pH Shampoo ($36). Be sure to really massage your scalp with your fingertips when washing to ensure you're removing any and all sebum, dirt, and product buildup.