Image: Graduation day © Thomas M. Barwick INC, Digital Vision, Getty Images

Have you ever wished that you could give your former self some advice? Unfortunately, we can't help you go back to high school and stop you from tattooing your then-favorite singer's face on your shoulder (Taylor Hicks' soul patrol for life!?). But we can help you look back several years from now and not similarly regret your money mistakes.

Here's some advice from our expert staff on what we wish we'd known about personal finance when we graduated from college, along with our best suggestions for someone just starting out.

1. To reach your goals, create a budget and stick to it

Nellie Huang, senior associate editor of Kiplinger's Personal Finance magazine, says: I made a budget so I could pay off my credit card debt. First, I subtracted from my take-home pay my fixed costs -- rent, utilities and $100 a week for lunch money, train money to commute to and from work, and "fun money." Then, the $150 I had left went toward the credit card bill.

It was tough. The rule was that I could go to the ATM only once a week. If I spent the $100 before the end of the week, too bad -- I couldn't go out with friends, I walked to work, and I skipped lunch if I had to.

2. Think about your future and start saving for it now

Stacy Rapacon, channel editor for Kiplinger.com, says: When I bought a house and had a baby a few months ago, I often thought about how much I'd frivolously spent in younger years on stuff that's useless now -- such as VHS tapes, DVDs, CDs and trendy clothes.

If I had saved that cash, I would've amassed that much more to put toward my down payment and supporting my child. I'm not saying I wish I hadn't spent any money on those fun things (sorry, my baby, but I wouldn't trade my complete series of "Buffy the Vampire Slayer" on DVD for anything); I just wish I'd spent a lot less then and saved for the future more.

3. Start saving for retirement as soon as possible

Anne Kates Smith, senior editor of Kiplinger's Personal Finance, says: Fund a 401k or IRA with whatever money you have. A little invested now goes a long way. Study a table that shows the magic of compounding and you'll understand why -- investing a couple of thousand dollars early on for a few years beats saving many times that amount for many more years later. So even if you think you can't afford to contribute, you must convince yourself that you can't afford not to.

4. Use your youthful energy to make more money

Pat Esswein, associate editor of Kiplinger's Personal Finance, says: To pay down debt more quickly or to beef up savings and income, do freelance work or take a second, part-time job. You will never have more energy than you do now (and if you're just out of college, you're used to working 16 hours a day). Whatever you do now will have a major payoff later -- say, when you want to get married, put a down payment on a house or take a trip around the world.

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5. Understand investing basics

Manny Schiffres, executive editor of Kiplinger's Personal Finance, says: Before you invest in anything, do a little homework to understand what you're getting into. Sometime in the mid-'70s, when I was in my mid-20s, I made my first investment -- a tax-free bond fund. I was so obsessed with cutting my tax bill, despite having a lowish tax rate, that I put my money into an investment that offered little potential for growth.

And because we were in a period of rising interest rates, I wound up losing a penny or two per share every day, and I had no idea why. Plus, I'd missed out on making good money by investing in stocks, which performed pretty well for the rest of that decade once the 1973-74 bear market ended.

6. Beware the dangers of credit cards

Mark Solheim, senior editor of Kiplinger's Personal Finance, says: Don't get a credit card until you are certain you have the money and discipline to pay off the entire balance every month.

When I graduated from college and wanted to take a summer publishing course, I didn't have enough savings to pay all my expenses. My dad gave me a "loan" in the form of one of his credit cards with the stipulation that I would pay off the balance on my own. My salary from my full-time publishing job was just enough to cover food, rent and gas, with nothing left over for debt payments. It took two years and a slew of extra odd jobs -- painting, mowing lawns -- to finally retire my debt.

7. Don't buy what you don't need

As for me, I wish I'd thought twice about buying a car after I graduated from college. As someone who grew up in small-town Ohio and attended college in Indiana, it didn't occur to me that in the big city of Washington, D.C., I could get by -- and save a ton of cash -- without my own set of wheels.

I took $239 a month out of my entry-level salary to make loan payments on the barely used Honda Civic I had purchased. Plus, I had the usual expenses for gas, insurance, property taxes, registration, repairs and maintenance. All of that for a car that was nice to have around but that I didn't really need. I thought about selling it, but Mother Nature eventually made the decision for me: Several tree branches fell on it as Hurricane Irene whipped past D.C. last summer, totaling the car. The insurance payback now serves as a nice cash cushion for emergencies, and I use car-sharing service Zipcar when public transportation won't do.

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