Let's be honest: the girl managed to find herself a killer curling iron in the fuselage. In between coming up with deep LOST theories (most of which relating to literature), I spend a lot of time trying to replicate Kate's fabulous loose curls. Here's my tried and tested regime for those with naturally wavy/curly hair (which has been an evolving process since 2003):
Wash and condition with a serious conditioner. Lately, I'm loving the Sunsilk Hydra TLC combo.
You may or may not want to finish with the John Frieda Gloss that coordinates with your color.
Step out of the shower, squeeze hair dry with your hands, add a dime-sized dollop of Hydra TLC conditioner to your ends. I know it's not leave-in, do it anyway. Skip it if your hair is not heat or color damaged.
Spray in some thickening spray; I prefer Bumble and bumble's.
Apply a bit of shine serum (like John Frieda's Frizz Ease) to the ends of wet hair.
Dry using a large paddle brush and a straightening attachment. Don't focus on making hair perfectly straight, just get most kinks out. Note: if your hair is VERY curly, you'll need to get all curl out. Use a round brush for styling hair around the face.
Separate the top 30% of hair with a clip and spray the roots UNDER it with Bumble and bumble's Hair Powder Spray in the color that matches your hair (I use blondish). This gives you bigger hair, which you can then claim is full of SECRETS.
Once hair is 95% dry, use a 1 1/2 inch curling iron with the clamp removed (seriously, use your tool box for the 3rd time in your life) to curl 2 inch sections. Here's how: wrap section around the wand (careful not to burn your hand or ear as there is no clamp--BTW, clamp = prom hair = not sexy). Be sure to keep the end of your hair uncurled--just the last inch or so. Hold for 30 seconds, remove iron and spray. Repeat. Start with the bottom of hair and work up to top layers. Spray once all of hair has been curled. I prefer L'Oreal Elnett which is so good, it's like, illegal in the US. New Yorkers can pick it up for around $17.00 at Pasteur Pharmacy on 34th Street between Park and Madison Avenues. Seriously, it's rarely sold in this country.
Once your hair has set (give it about 10 minutes), you can separate the curls by raking your fingers through lightly to further eliminate the prom factor.
Finish with gloss spray; I enjoy Bed Head Headrush Shine Spray.
Dr. Jack Shepard (I challenge anyone to tell me that that other Doctor Shepard on ABC is hotter) will barely be able to CONTAIN himself.