The product: Ouai Treatment Masque ($30 for eight packets)
Why we love it: Days spent frolicking in the water or even just traveling can dehydrate your hair. Celebrity hairstylist Jen Atkin created these single-packet masks for her Hollywood clients. The masque will leave your hair velvety after one use (Jen recommends throwing it on your mane before a workout and then washing it out in the shower). Since you can throw it out after one use, it creates room for new purchases.