Type 1 hair could also be thick, like Demi Lovato's. "While for fine, straight hair, you want to use really lightweight and volume-pumping products, for thick hair, you want to use something that is more moisturizing," says Cynthia. Even though natural oils will still make their way through your hair, the thicker strands will absorb more of it, so you want to add a little bit of moisture, concentrating on the ends. "Thicker straight hair tends to have a lot more volume, so you might occasionally need to weigh it down to control it," she adds.
Having a hard time figuring out if your hair is thin or thick? Here are two tricks: "Usually fine hair doesn’t hold a curl as well as thicker hair does. Plus, there’s simply less of it if it's fine, so if your ponytail is small, you know where you stand."
Product recommendations: A small amount of oil on the ends of your hair after washing is all you need to keep it soft. Try Ouai Hair Oil ($28).