Typically, oils and serums can be really heavy — especially on fine hair like mine — but K-Pak Color Therapy Restorative Styling Oil (available at Joico salons) never is. It gives incredible shine, and smooths away frizz and flyways without weighing hair down. It works as well on fine hair as it does the thickest, coarsest hair, which is why I love it.
For fine hair like mine, rub a teeny drop between your hands and smooth over dry hair from midshaft to ends. For hair that's thicker and coarser, apply one pump to damp hair (again from the midshaft to ends), blow hair dry, and then reapply as needed for additional gloss and control. The real key to using a serum or oil is to apply only from the midshaft down — never to the scalp — to prevent hair from looking dirty or greasy.