Clip-in extensions can be a great way to do a trial run before you pony up for professional extensions, or they can add some volume and length for special occasions. But since they’re basically metal clips on your hair, Jeanne says you shouldn’t use them often as they can be majorly damaging. And don’t ever sleep in them, they’ll totally bend your hair and make it brittle, not cool.

If you’re going to use them, buy enough for your whole head and carefully follow the instructions. It also helps to gently tease your hair and spray with hairspray before clipping them in so there’s more grip. If the ones you buy don’t exactly match your real hair, a stylist can cut and color them. Jeanne says curling the extensions can also help them blend in more naturally with your hair.

Next: Go with a pro