Did you ever have a guidance counselor tell you to "sell yourself" if you want to succeed? Well, there are ways you can literally sell yourself to make some cash -- and not in any way that will land you in trouble with the police.

We’ve rounded up 14 completely legal and medically safe ways to make money from your body, using just what your mama gave you.

14. Sell your hair

Beautiful young woman portrait in lavender field. Attractive brunette girl with long curly hair style in white dress dreaming.
VAndreas / Shutterstock
If you can cut off more than 10 inches of your hair, you might be able to sell it.

Potential earnings: Up to $1,500 +

There’s big money in the hair business, and wig makers and stylists will pay handsomely for the stuff growing on your head.

If you’ve got long hair and can cut off more than 10 inches, then you might be able to sell it. The ideal length is usually 15 to 35 inches or longer.

The color and health of hair also affect the value. Undamaged hair in great condition and hair that has never been dyed (known as “virgin hair”) are best for selling, according to the Victorian Hairwork Society.

Natural blonde hair and brown hair with natural color variation will net a decent profit — and red hair, that rarest color, sells for the most. You can sell your hair to the Victorian Hairwork Society or online at Buyandsellhair.com, Hairsellon.com or Craigslist.

13. Donate your eggs

Patient undergoing egg retrieval procedure in theatre
Monkey Business Images / Shutterstock
Eggs are collected through surgery.

Potential earnings: $5,500-$8,000

Donating your eggs to help couples complete their families might seem like a nice way to make money — but ladies, don’t be fooled into thinking it’s easy. The reason the potential earnings are so high is because you’re paid for the time and physical stress it takes to prepare your body before eggs can be donated.

A potential donor should usually be under 30 years old. If she can pass the thorough medical screening and is eligible to donate, then she’ll start taking fertility drugs to increase ovulation and begin seeing a doctor regularly for checkups.

Finally, her eggs are collected via surgery.

Potential complications include discomfort during the increased ovulation, developing ovarian hyper-stimulation syndrome, and the inherent risks of surgery.

12. Become a human billboard

Getting a tattoo. Close-up, toned image
Miki Studio / Shutterstock
Some people have made money getting tattooed with corporate logos or messages.

Potential earnings: Unclear

Forget boring unpaid body art! Why not get a tattoo and make some money?

Back in 2005, Andrew Fischer went on eBay and auctioned off his forehead space for advertising. The winning firm paid $37,000 to have Fischer wear a temporary tattoo of the company logo on his head for one month.

A few people went further and got permanent tattoos of website logos. One man was allegedly paid more than $200,000 for tattooing 15 company logos onto his body. Of course, since it was in the middle of the dot-com boom, some of those firms are now long gone.

(How much does tattoo removal cost, again??)

11. Sell your swimmers

real Human Sperm and cell bodies photomicrograph viewed under a 100x objective. Panorama.
Carolina K. Smith MD / Shutterstock
Sperm banks pay handsomely for donations from healthy men who meet their requirements.

Potential earnings: Up to $1,500 per month

Not everyone is an ideal candidate, but sperm banks pay handsomely for donations from healthy men who meet their criteria.

Typical requirements include being between 18 and 39 years old, nonsmoking, drug-free, having low risk of genetic disease and standing at least 5 feet 10 inches tall.

If you measure up, most sperm banks will offer a contract asking for one to three deposits every week for a minimum six months to a year. We're guessing you'll enjoy the money — and the work.

10. Become a parts model

hand with ring
kozgunaydin / Shutterstock

Potential earnings: $1,000-$5,000 per day, or $75,000+ a year

We may not know them by name, but successful body parts models are in high demand for print ads, TV commercials and more.

The most sought after parts for modeling are hands, feet and legs, but agencies also look for attractive eyes, teeth and lips, hair, backs and stomachs, on both women and men.

If you think you’ve got nice parts, then you’ll want to have them evaluated by a professional, or sign up for ModelScouts.com, an affordable model management company.

9. Be a guinea pig

Doctor is preparing a sportsman to the medical trial
Photographee.eu / Shutterstock
You can make thousands of dollars participating in a medical trial, but beware the risks.

Potential earnings: Up to $5,000 per project

The government, hospitals and drug companies routinely run clinical trials to test new medicines and treatments for a wide range of diseases. Some trials want healthy participants, though many seek people who have specific medical conditions needing treatment.

You should be aware that this isn’t always “easy money”: Trials can be hard to handle because of all the poking and prodding researchers will perform — often in ways (and places) you don’t expect.

Generally, the less information researchers have about a drug’s or treatment’s risks, the more you’ll get paid. But since all trials carry some risk, learn as much as possible before signing up.

You might want to have some money put aside in case you’re left dealing with an unwanted side effect.

8. Sell breast milk

breast milk frozen in storage bags for baby
Karunyapas / Shutterstock
There's a healthy market for breast milk online.

Potential earnings: $1 to $3 per ounce

For real. Selling breast milk online is an increasingly popular option for moms who produce more milk than their babies need. Potential buyers include parents who can’t produce enough milk for their babies, and bodybuilders who drink it "for building muscle mass."

But if you’re thinking of selling your milk online, keep in mind that "milk fetish" is a real thing too. Tip: Don't Google that at work!

Hygiene also is a major concern with selling breast milk. One study tested over 100 samples of milk from a web-based seller and discovered that almost 75% were tainted with a high level of bacteria or with bacteria connected to illnesses.

A safer option might be to donate to a nonprofit milk bank, where the donors are screened and the milk is processed before being given to babies who need it.

7. Hug it out

Positive happy people hugging each other
Dmytro Zinkevych / Shutterstock
Hugging therapy can be conducted in a group setting.

Potential earnings: $60 per hour

Sometimes, we all just need a hug — and that’s the idea behind the growing industry of professional huggers and cuddlers.

Pro huggers describe their work as a free-form talk and physical touch-based therapy that helps clients relax in a comfortable environment rather than a clinical setting. Sounds legit, doesn’t it?

Professional cuddlers offer nonsexual hugs, spooning and gentle caresses on the arms or back. A typical session can happen one-on-one in private, or in a group setting.

Pro huggers can easily make $60 an hour or more. Doesn't that sound like something you'd want to get your arms around?

6. Donate your blood or plasma

Blood Plasma Donation process, hand squeezing a rubber ball
RUCHUDA BOONPLIEN / Shutterstock
You might earn hundreds of dollars a month donating plasma.

Potential earnings: Up to $300 per month

Your blood or plasma can bring in a decent profit since you can usually donate twice a week, making between $25 to $50 per donation.

You can give blood or plasma no matter what your blood type, as long as you are healthy and free of blood-borne diseases. There's virtually no risk to your own health.

One thing to note is that the U.S. government doesn’t allow hospitals to use blood taken from paid donors. So if you’re paid for your donation, your blood will likely go to pharmaceutical and drug companies for use in product development and testing.

5. Model for art classes

Painting a model/Painting easel with a fresh new white canvas on prepared for painting and a model in the out of focus background represented by a wooden dummy.
Sorin Vidis / Shutterstock
If you're willing to spend an hour or two in front of strangers, you could make some money modeling for art classes.

Potential earnings: $20 per hour

Officially known as “figure modeling,” posing is still a classic easy-money move. All you need to do is unbuckle your belt, assume the position and sit still for an hour or two while aspiring artists sketch or paint your glorious figure.

If this sounds like your thing, then get in touch with local community centers, colleges and art schools and check if they’re looking for models.

Alternately, you can post a classified advertisement — but that might bring some odd responses.

4. Become a surrogate mother

Pregnant Woman, Ultrasonography
Image Point Fr / Shutterstock

Potential earnings: $40,000-$50,000

In surrogacy, a woman essentially rents out her uterus for nine months to a carry a baby for a couple who — for one reason or another — are unable to have their own children.

It’s usually a very rewarding experience, but far from an easy one.

A gestational surrogate can be in her early 20s to about 40 years of age. The entire process can take up to a year and a half to complete, including the surrogate’s application, lengthy physical and mental screenings, and criminal background and financial checks.

A surrogate signs a contract agreeing to give up the baby when it's born. As with all pregnancy and birth, there are health risks throughout the process.

3. Stay in bed for 70 days

Sleep Apnea Diagnostic medical device Kit attached to the finger and the human nose, which lies in bed
Koldunov Alexey / Shutterstock
Can you spend a couple of months in bed? You could earn thousands of dollars in a NASA research project.

Potential earnings: $18,000

It’s true: NASA will pay you to lie in bed around the clock for 70 days. With this experiment, NASA scientists are studying changes that an astronaut's body would experience in zero gravity.

Keep in mind that participants should have the same physical and mental attributes that a real astronaut would.

This includes a high tolerance for physical discomfort, serious mental endurance, normal blood pressure and a willingness to undergo a battery of tests while hooked up to strange scientific equipment.

2. Sell your spit

A scene from
Courtesy of Netflix
Donate your spit, and you could wind up feeling that you've landed in your very own episode of "Black Mirror.

Potential earnings: $50 per donation

A company called DNAsimple will pay you $50 to donate a sample of your DNA-containing spit. All you have to do is sign up with your medical details, and they’ll send you a spit donation kit if you’re matched with a study looking for participants like you.

So, what’s the problem with donating your DNA and not knowing where it’s going? We all know that companies can barely keep our financial data secure — so just think of what DNA hackers could do if they got hold of your spit.

Some possibilities include cloning, planting DNA at crime scenes, and using your genetic code to develop bioweapons. Welcome to your very own episode of Black Mirror.

1. Make a crapload of money

White toilet bowl and Toilet Paper.
SThanaphat / Shutterstock

Potential earnings: $40 per donation, plus bonuses!

Openbiome is a firm that will pay for your poop.

Yup. We've been flushing gold down the toilet our whole lives.

The company collects stool so intestinal bacteria from a healthy individual can be given to someone who’s severely sick due to a lack of healthy gut bacteria. The fecal transplants seem to offer a promising solution to Clostridium difficile (C. diff), a deadly antibiotic-resistant gut infection.

To become a donor, you’ll need to undergo health screening, be 18 to 50 years old and have a body mass index below 30. The program is open only to residents of Boston, Cambridge and Somerville, Massachusetts.

Once approved, you can donate your magical poop several times a week for 60 days — and you’ll get a $50 bonus if you donate five days a week. Now that’s some crazy, er, stuff!