Anyone who knows how to really wield a blow-dryer can get their hair pretty straight with that alone. But when you want super sleek, shiny strands, a flat iron is your best friend. They’re a lot easier than struggling with a dyer and round brush to get the perfect blowout, saving you loads of time and effort. The best flat irons aren’t just for straightening, though — the surprisingly versatile tool can be used for everything from creating flips to S-waves, beachy waves and even curling. Plus, thanks to ionization, flat irons majorly cut down on frizz, leaving smooth, glossy hair behind. To prevent heat damage, start with the lowest-temperature setting and if that doesn’t get work, gradually work your way up the heat scale. Otherwise, starting off with the highest heat can instantly scorch strands, leaving you with permanent, irreversible damage. A too-high temperature will fry the outer cuticle layer, making hair more porous, so it’ll be tough for it to retain moisture, leading to dry...