Got a bad haircut? Buy clip-in hair extensions. Fried a chunk of your hair off? You need clip-in extensions. Want to channel your alter ego? The answer's clip-in extensions. Whatever your reason for clip-in extensions, the outcome is the same: longer, thicker hair in a matter of a few snaps. The best thing about clip-in extensions is that you don't need to drop an entire paycheck on them and you can apply them all by yourself—AKA they're busy girl-approved. Here, celebrity hairstylist Glen Coco—the man behind the hairstyles of Chrissy Teigen and Josephine Skriver—shares his tips on matching the clip-ins to your hair color, the secret to keeping them in all day, caring for them and more.

Who is and isn’t the ideal candidate for clip-ins

Anyone looking to add length or add thickness to their hair should consider clip-in hair extensions. Only really, really fine and fragile hair shouldn’t wear clip-in extensions to avoid any extra weight or tension on the hair. 

How to know how many packs to buy

If it's length you're trying to conceal, most likely you’ll need more hair, 2-3 packs ideally. If you’re not changing the length dramatically and you’re just adding thickness, one pack is plenty. It also comes down to personal preference as well, and the quality of the hair. I like The Hair Shop. They have a variety of natural colors and a variety of lengths. They also have a multitude of bang clip in extensions, as well as ponytail pieces to make styling very easy. 

How to match your hair color

The best thing to do is to always go slightly lighter than your hair color, but be sure it’s in the same tonal family. For example, if your hair is warm blonde, you wouldn’t want to get a lighter cool blonde. You’d want to still get a warmer lighter blonde. If the color isn’t a perfect match, I like using Rita Hazan root color spray at the top of the extension to create a root,  followed by a boar bristle brush to blend the root spray into the extension. That allows the top of the clip-in extension to match the root of your natural hair. 

How to prepare the hair before clipping in

I personally don’t like to use hair spray before applying each clip-in hair extensions because I do a lot of hair changes and I don’t like how it makes the hair feel. I just do a gentle root backcomb on each section to give the extension something to grip to. Either dirty or clean hair is fine. But if you apply your clip-ins on clean hair, you’ll need to add something for the clip-in to grip to, and that could just be a tease with your comb, some dry shampoo, or hair spray. A nice clean and strong backcomb will keep the extensions in place on a long day.

What not to do with clip-ins

One mistake people always make with clip-in hair extensions is putting them too high on the head so you can see them through your natural hair in the crown. Another mistake is also positioning around the face to make them conceal shorter pieces. The key to avoiding tracks from showing includes applying at a diagonal, using root spray and teasing the section on the top to hide more extensions. 

Caring for clip-ins  

I’d wash your clip-in hair extensions as little as possible to have them last as long as possible. I recommend any moisturizing shampoo.  Over washing extensions, color processing, and excess heat styling will ruin the integrity of the clip-in. When it’s time to brush clip-ins, I like to use the Sheila Stotts Removal Brush, and a Mason Pearson Brush

How to apply clip-ins before creating a high ponytail 

I clip the extensions in a circle around where the ponytail will live. 

Sleeping in clip-ins

I don’t recommend it unless you need to preserve your style for the following morning. It can pull the hair where they’re clipped in and cause breakage in any areas of tension. But if your hair stylists put them in for you, and you know you won’t be able to replace them properly, do the damn thing.

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