No one wants flat, limp hair — and styling it proves even more challenging — so we get why you're a little envious when you run into that woman with the impossibly thick and bountiful locks. Well, that can be you, too. Just follow these tips and tricks straight from the pros to get the full, luscious hair you really want.

1. Pick a thickening shampoo and conditioner.

If you don't want to try expensive extensions or experiment with supplements, there's always the tried-and-true method of volumizing: picking a thickening shampoo and conditioner. "I prefer to go with the work-with-what-you-have approach by using hair products and styling tools to create volume, thickness, and texture," says Devin Toth

2. Cut it at your shoulders or above.

Though "longer hair" and "thicker hair" are sometimes used interchangeably, in reality, they're totally different. "If you have thin hair, opt for a cut that is short to medium length," advises Nick Penna, "Often thin or fine hair that's very long can look stringy and even thinner since it's weighed down by the length." Searching for the perfect cut for your thin hair? We've got three long bobs that will work wonders.

3. Do a little strategic teasing.

Teasing your hair doesn't have to turn you into a full-on 1980s rockstar. If your locks tend to fall flat, use a clean, brand new toothbrush to gently tease it at the roots, giving the appearance of more volume.

4. Add a root lifter to your regimen.

Misting this handy product can give you a fuller look without much effort. "Hair flat to the head always looks more thinner than hair that is lifted at the root," explains Penna. "Women can use a root lifter to give their hair bounce and volume right at the start of the hair shaft."

5. Ask your stylist for highlights.

If you're open to coloring your hair, adding a few foils into the mix could be the right way to go. "Highlighting hair adds the look of depth to strands," says Penna. "It gives your mane dimension, which creates the illusion of fuller locks instead of flat, single-toned hair." Talk to your stylist about the most flattering highlights for your face, or bring a photo of a style you already love to your consultation.

6. "Color in" your scalp.

The more of your scalp you can see, the thinner your hair will appear. Fill it in a bit with a medium eyeshadow brush and eyeshadow the same color as your hair. The results speak for themselves: Just make sure not to try this trick on a day it's going to rain!

7. Use a ceramic brush when you blow dry.

Using the right post-shower tools can go a long way to making your hair appear thicker and more bouncy. "I like to use a ceramic barrel brush to build volume during a blowout," says Toth. "An ionic dryer emits pure negative ions to reveal smooth, frizz-free results." Not sure which brush is which? Check out our handy hair brush guide.

8. Start taking supplements that benefit your hair.

"Female-patterned hair thinning is related to our hormones and the sensitivity of the hair follicles to the hormones," explains New York City dermatologist Dr. Hadley King, MD. "Hormonal prescription medications such as some oral contraceptives and spironolactone can be very effective in making hair thicker." In addition to the prescription stuff, Dr. King says over-the-counter minoxidil, a supplement that helps slow hair loss, is also effective for some women. But heads up: It can be accompanied by side effects like burning and irritation, as well as further hair loss.

9. Use your dry shampoo in a whole new way.

Dry shampoo is one of the beauty world's modern miracles, but it does more than make your dirty locks look clean. Spraying a bit of dry shampoo along your roots, then massaging it in can give you a little boost of volume.

10. Invest in high-quality extensions.

When applied by a pro, hair extensions are an effective, natural-looking way to make your hair appear thicker — as long as you go to a seasoned stylist who has a lot of experience with extensions, of course. But it's important to note that there's one big catch: the price tag. According to the experts at Angie's List, a set of extensions can cost you anywhere from $275 to $1,400 — that's a lot of dough to drop on your hair.

11. Keep your hair healthy.

This seems like a given, but getting great-looking hair is nearly impossible when you're constantly damaging it. "If women want thicker-looking hair, they should immediately stop flat ironing it and refrain from using too much conditioner in the shower," says Toth. Taking precautions like using heat protectant spray, not over-washing your hair, and always using SPF on your locks before you step into the sun can totally rescue your hair, making it look thicker and stronger in no time.

Source: GH.com

Nice....
Over to the ladies

This seems like a given, but getting great-looking hair is nearly impossible when you're constantly damaging it. "If women want thicker-looking hair, they should immediately stop flat ironing it and refrain from using too much conditioner in the shower," says Toth. Taking precautions like using heat protectant spray, not over-washing your hair, and always using SPF on your locks before you step into the sun can totally rescue your hair, making it look thicker and stronger in no time.

I'm going to bump this thread and put my two cents here.
Yes, there's no universal key to have great-looking hair. There are so many aspects to consider during your daily hair care routine, even the article above can't cover it all. From my perspective, if you want to have thicker-looking hair and don't want to give up on using a flat iron then I would recommend checking this article on Mystraightener about those designed for black hair. I think this might be useful.