Photo: Davies & Starr

Conventional beauty wisdom has it that you should use a mask once a week to repair damaged hair. But we have a secret: In the bone-dry, hair-parching dead of winter, we treat ourselves to one after every shampoo—and experts say we're onto something. "Masks have much higher concentrations of moisturizers than regular conditioners, so even if you're short on time, you'll benefit from using one," says Cheri McMaster, principal scientist for Pantene. So pick your poison (or protein or panthenol). A few of our favorites:

1. Frequent rendezvous with a colorist or trysts with a flatiron leave hair porous. The protein in Aveda Damage Remedy Intensive Restructuring Treatment ($26) seeps into weakened areas, fortifying hair. As with all masks, if your hair is very brittle, coat it from roots to tips; the fine-haired should avoid the crown.

2. & 3. Coarse hair requires a thick, emollient-rich formula. The intense moisturizers in Privé Formule Aux Herbes Intensive Mask ($25) and Skin an Apothecary French Hair Paste ($25) seal the hair shaft to spin strawlike strands into silk.

4. When you have the time (and no possibility of a surprise guest), slip on a granny-style plastic shower cap after applying a mask and sit tight for 15 minutes or so. Trapping heat (direct a quick shot from your hair dryer under the cap for a little extra) helps liquefy the conditioners, intensifying the treatment. Each single-dose, panthenol-packed jar of Alberto V05 Total Hair Recovery ($5.50) comes with its very own plastic topper.

5. Do deep conditioners leave your hair feeling more limp than luxurious? Try J.F. Lazartigue Moisturizing Mask ($51). Massage it into damp hair and let the coconut oil sink in before you shampoo away any residue that could weigh down hair.