If you want to take your curls from pretty good to life-changing, incorporating hair masks into your routine is the way to get there. We spoke to curly hair expert Pia Vivas, a stylist at Ouidad's Santa Monica flagship salon, about how to get the most out of using a hair mask.How do I choose a hair mask?"There are two types of hair masks - protein-based masks and pure moisture masks," Vivas says."Protein-based masks are best for hair that needs strengthening, such as bleached or damaged hair." (Some hair types, such as low-porosity hair, don't respond well to protein-based masks. Read more about protein treatments for curls here.)Moisture-based masks, such as the new Ultra-Nourishing Intense Hydrating Mask, are great for any curl type experiencing dryness. This type of mask can be used as often as you like-even in place of your conditioner.What will a mask do for my hair?Not only will a moisture mask rehydrate your curls, the right formula should help with detangling, too. "Slip is really important when it comes to preventing breakage," Vivas says.If you use a hair mask the right way, it will replenish nutrients to help strengthen and fortify your hair. If you use a protein treatment every three weeks or so (which is what Ouidad recommends), you can use a moisture mask in between treatments to keep your curls hydrated.Do I apply a mask on wet or dry hair?A mask's nourishing ingredients absorb better when applied to wet hair. For best results, apply your hair mask on clean curls first. "Make sure you get everything off the hair to start with a clean canvas. Because oil breaks down oil, use an oil-based cleanser to remove buildup (especially if you use coconut oil in your hair, which can be hard to wash out)," Vivas says. Rinse, then follow with a clarifying shampoo. Once your hair is clean, apply your mask.How long should you leave a hair mask on your hair?For best results, apply your hair mask in the shower - the steam will help to open your hair's cuticle. Leave the mask in your hair for at least two minutes, and up to 10 minutes.For more tightly coiled textures or less porous hair, you'll want to use your fingers to mechanically work in the product, Vivas says. Then wrap your hair in a hot, damp towel for five minutes to help "steam" the product into the hair (or use a hair steamer if you have one).Can you leave a hair mask on for too long?Short answer: It depends on the hair mask you're using. For moisture masks, like Ultra-Nourishing Intense Hydrating Mask, it's fine to leave the mask in overnight (just be sure to cover your hair with a cap to protect your pillow!).For protein treatments, always follow the label instructions, since leaving the hair mask on for too long can cause hair to absorb too much protein and lead to breakage.Will a mask fix damaged hair?"If your hair is unhealthy and needs to be trimmed, a mask won't fix it," Vivas says. Your best bet: see a Ouidad-certified stylist to trim any dead or damaged ends first. Your stylist can also recommend the best hair mask for your specific curl type and needs. After your trim, use a mask regularly to prevent breakage. Congratulations - you're on your way to long, strong, healthy curls.More curly hair care advice: Keep Your Curls Damage-Free This Summer VIDEO: How to Hydrate Dry or Damaged Curls