When it comes to hot weather hairstyles, the go-to answer is always a ponytail -- and for good reason! The easy-breezy look is both functional (you hair is off your neck and forehead, helping you cool off!) and wildly adorable. This summer, the look du jour is the ultra-high, super-dramatic 'I Dream of Jeannie' pony. To do: sweep your hair into an elastic at the tippy-top of your head (if your strands are short, attach a fall). For a chic finishing touch, wrap a piece of hair around the elastic. Voila! Instant summertime sexiness.