It's the secret to the glamorous cascade of curls that Hollywood stars regularly show off on the red carpet. We're talking about curling irons. "You can change the whole texture and personality of your hair in just a few minutes with a curling iron," says Mezei Jefferson, a Chicago-based salon educator. "It will also help boost volume and add fullness to baby-fine hair."

There are a variety of different curling irons that create curls of different size and tightness. Here's how to find the one that's right for you.

Spiral curls

These curling irons have raised ridges on the barrel. To create the telephone-cord curls of Sarah Jessica Parker or Mariah Carey, simply twist your hair around the spiral pattern. The closer the grooves, the tighter the curls. For cascading ribbon curls with volume at the roots, choose a spiral iron with a tapered barrel.

Tips:

• Work with diagonal sections of hair to get closer to your scalp and create small bouncy curls.
• After you curl a section of your hair, pin it to your scalp to keep your curls intact as you continue styling the rest of your hair.

Loose curls

Think romantic curls a la Carrie Underwood or the Old Hollywood waves of Megan Fox. To create soft, loose curls, choose a spring curling iron with a barrel size of at least 1 inch. The longer your hair, the larger the barrel you'll want: Opt for a barrel of 1 1/4 to 1 1/2 inches for mid-length hair, or 2 inches if your hair is shoulder-length or longer. Spring curling irons are a great tool for novice curlers -- the clip helps you keep a firm grip on your hair as you work.

Tips:

• Begin working from the middle of the hair shaft. Roll hair in the direction of your scalp. Then open the clip and feed in your ends.
• To protect hair, use as little heat as needed. Start with a temperature of 300 F (150° Celsius). If that doesn't give you the hold you want, gradually move on to hotter settings, increasing heat by 25 F at a time.