Well, if you're curly or wavy and fine-haired, there's no better lightweight product than Ouidad Moisture Lock Leave-In Conditioner—it'll keep your hair bouncy all day. If you want a little more weight to tamp down frizz, Rene Furterer Leave-In Nourishing Cream is a great, slightly richer option. For limp, straight hair, try Verb Leave-In Mist. It detangles and hydrates, but it's so light that even wispy curls won't get pulled down.

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