What they’re good for: Commonly made of ceramic— there are many titanium versions, too—curling irons feature a clamp to keep the hair contained as it heats it to set the curl. They come in a variety of barrel sizes depending on the type of curl desired: 0.25-inch is the smallest, and good for ringlets; 1.5 inches is the largest, and great for loose waves, and also long hair.
Expert tip: For finer hair, Roszak says temperature and barrel size are important factors. “You don’t want your iron too hot or not hot enough—both can result in the flattening of curls—or too small. The sweet spot is usually around 375 degrees and 1 inch. Immediately after curling each section, spray it with a lightweight hairspray to help hold it.” And for all hair types, Roszak suggests letting the curls fully cool before breaking them up.
One to try: Powered by the brand’s breakthrough Rapid HeatIQ technology, T3 Curl ID ($235) optimizes the heat for every hair type based on customized settings to produce perfect curls.