"Using too large of a rod" is one of the biggest mistakes women make when curling their hair, says Sarah Potempa, celebrity hairstylist and creator of the Beachwaver curling iron. Not only do large rods create looser curls, she says, they prevent "an even curl pattern from being created throughout the hair."

Try a curling iron that's about a quarter-inch narrower than the one you're using now, Potempa suggests. "For example, if you are using a one-inch barrel and your curls are falling, then try using the Beachwaver S.75 instead," she says.

Another way you might be going wrong when you curl your hair? "Not investing in the right tools," Potempa says. "If you use a cheap curling iron, then your curls will fall more quickly."

Poorly made or old, worn-out irons may radiate heat unevenly, frying some strands while others are cool AF.

Get rid of your iron if you're working with a vintage model. Or, if your iron's plates are metal, upgrade to one with even-heating ceramic or tourmaline plates.

Remember: A high-quality iron doesn't have to be expensive. Hot Tools curling irons are popular with pro hairstylists and start at about $40.

Shampooing without conditioning might sound like eating a peanut butter sandwich without jelly (i.e. wrong, awful, totally unthinkable).

But Nicole Contrastano, stylist at Pierre Michel Salon in NYC, says skipping conditioner is key to make curls last all day. "It makes the hair too soft, which makes [curls] not hold that well," she says.

By washing with shampoo alone, you'll rough up your hair's cuticle just enough to help curls stay intact.

Just as conditioner can make your hair too smooth to hold a curl, styling creams and oils also "weigh it down," Contrastano says. You need styling products to give your hair texture and grip, not make it smoother.

Before you curl, think about using light stylers -- e.g. mousse or spray -- to give your hair light hold and bounce. Save greasy products for blowouts or slick hairstyles like ponytails and topknots.

If you have trouble keeping curls locked in place, you're gonna need to use styling products before and after you go at your hair with an iron. Potempa suggests a cocktail of mousse and heat protectant, whereas Contrastano likes using texturizing volume spray.

Spraying your curls with hairspray after styling is an obvious move to keep curls in place. (Flexible hold hairspray, please; you want these curls to move, right?) But the real trick is waiting to spray until after your curls have cooled, Potempa says.