Fine or thinning hair can easily become damaged under too much heat, so cooler temperatures (i.e., those under 300° F) are ideal for these hair types. If you have very curly, course, or thick hair, then higher temperatures upwards of 400° F may be more suitable to your needs. With the ISA Professional Titanium Flat Iron, you can cool it down to 265° F if need be and also crank it up to a whopping 450° F for textured styled.
With well over 25,000 reviews, the HSI Professional Ceramic Tourmaline Ionic Flat Iron is one of the best straightening irons you can get, but because of its thin build and rounded plates, you can also use it to curl your hair. It’s got solid ceramic plates to reduce damage, evenly heat hair, and promote shine, and if you’re a traveler, it’s got a dual voltage that can be used anywhere in the world.
We usually roll our eyes at oil-infused heat tools — but you can actually watch this oil being sucked right out of the refillable cartridge in the handle. When you press the iron closed over your strands, the oil vapor seeps through tiny holes to condition and straighten your hair. And don't worry fine-haired friends: It made our tester's hair silkier, but not like she'd dipped it in an oil vat.