My curls require more nourishment during the winter, when it's too cold outside to skip the blowdryer and air dry my hair each morning. For deep conditioning, I've been using Amika's Obliphica Nourishing Hair Mask as a weekly treatment and love how it hydrates without weighing hair down. The rich, creamy mask (made with vitamin C and Obliphica and Moroccan Argan oils) promises to seal split ends and improve shine and elasticity, and can also be used as an everyday conditioner. The generously-sized jar is a plus, and so is the light, fruity scent. I have a feeling this will become a shower staple for all seasons. The mask sells for $40 at --Dana Wilson