Frizz-Ease is the gold standard of frizzy-hair products and with good reason. It uses silicon to moisturize the cuticle, making hair incredibly soft and instantly taming any fly-aways. Added bonus: its UV filter will protect hair from drying out in the sun, making it perfect for colour-treated hair!
John Frieda Frizz-Ease Original Formula hair serum ($16, at drugstores)