According to the National Center for Education Statistics, 20.4 million U.S. students are attending college this fall.

With the average cost of undergraduate tuition, fees, room and board standing at $16,757 at public institutions, $43,065 at private nonprofit institutions and $23,776 at private for-profit institutions, collegian's financial budgets will be tight, and extra cash hard to come by.

The good news? There are multiple ways for college students to save money, even on campus, that gives them more financial leeway throughout the school year - if they're diligent and creative about finding good ways to save money.

Some college students have already tapped into that cash savings vibe, and they advise other students to get on board.

"I paid my way through college by running a house-painting business and teaching piano," says Andrea Miller, founder of MusicStudioStartUp.com near St. Louis. "Now I blog about entrepreneurship for young music teachers. It's helped me graduate nearly debt free and get a head start on a career."

There are plenty of other ways to earn and save money while in college. Here are some of the best ideas:

More of What's Trending on TheStreet:

Take advantage of student discounts - "Lots of brick-and-mortar stores that attract college-aged shoppers will give students a discount," says Leah Ingram, author of the new book The Complete Guide to Paying for College. "All you have to do is show your college ID. In my research, I found that most stores offer a 15% discount. This is true even at retailers not located in a college town."

Use the "envelope system." - Financial experts tout the "envelope system", where college students can put cash into an envelope each month for purchases like clothing, entertainment, and repairs. "Then, when you hit your goal or if something breaks, you can spend the money without wrecking your budget," says Brian Morris, communications coordinator at DirectTextbook.com. "We call them budget busters, and the envelope system protects against them."

Get in on the gig economy - If you can write, design, or complete data entry tasks, you can find work on sites like Fiverr and Upwork, says Morris, and make some extra bucks. "You could earn as much as a part-time job, but have the flexibility to work around your school and study schedules," he says.

Take advantage of automatic bank savings - "I'm a big advocate of making your savings automatic," says Ralph Latayan, a 2014 college graduate who now works on Wall Street. Latayan advises setting up your checking account so that a certain amount is transferred from your checking to your savings account without lifting a finger. "This not only allows you to be consistent with your savings, but also minimizes the emotional burden that normally comes with putting money aside," he explains. "You can't miss the money if you never touched it. The next thing you know, you will have a decent amount waiting for you in your savings account."

Ditch the dorm - Live off campus, advises Mike Sullivan, a consumer educator at Take Charge America, a national nonprofit credit counseling and debt management agency. "While dorm life is convenient, it's also pricey," Sullivan says. "After your first year, find a few roommates and look for a cheaper apartment or house near campus or, if you are close to home, live at home to save even more money."

Cut ATM usage and fees - ATM fees can really add up if you're taking out cash somewhere other than your bank. "Go with a bank that offers ATM rebates each month to make sure you're getting this money back," advises DNB First Bank, in an email statement.

Slash textbook costs - One of the biggest expenses for college students is their textbooks, which can cost hundreds of dollars each semester, says Matt Brooks, co-founder of SEOteric, a web site development and SEO firm based in Watkinsville, Ga. "To save money on textbooks, students should consider purchasing their books online and then sell them online once the textbook is no longer needed," Brooks states. Websites such as BookScouter.com provide a platform for students to search easily through a list of online websites in order to find their book for the cheapest price, he notes. "BookScouter also allows students to find the best online vendors to sell their textbooks," Brooks adds. "Students can compare prices for buying both new and used books as well as sort through which websites offer renting and textbook buyback options."

Don't eat on campus, especially if you are a commuter - "I commute every day to school and will eat at home or bring a snack to eat in between classes," says Arianna Nunez, a junior at Seton Hall University and an intern at TopCashBack.com. "Food on campus is expensive and unhealthy. By packing my own lunch, I save money and eat healthy." Nunez also saves money by brewing her own coffee. "I used to purchase coffee or tea on my way to school, but realized I was spending $20 to $30 a week alone on caffeine," she says. "I decided to skip Dunkin Donuts and Starbucks altogether and purchase my own tea bags and tea infuser to save money. The money that I save each week goes toward my commuting costs or into my savings for when I actually need it."

College is demanding enough without being short on cash. Mitigate that problem by making the savings moves listed above, and making money management an unofficial - but critical - major while you're on campus.

More of What's Trending on TheStreet:

More from Personal Finance

What Is Tiger Woods' Net Worth?

What Is Tiger Woods' Net Worth?

How to Fill Out a Money Order: 5 Simple Steps

How to Fill Out a Money Order: 5 Simple Steps

Who Owns Netflix? CEO Reed Hastings' Career

Who Owns Netflix? CEO Reed Hastings' Career

How to Become a Financial Advisor: What to Know

How to Become a Financial Advisor: What to Know

How to Prevent Debt From Destroying Your Retirement

How to Prevent Debt From Destroying Your Retirement