For many of us, our twenties are (or were, in my case) a time for really sorting out some of the keys to our long-term personal and professional happiness. And the last thing you probably think you need is a lesson in fertility (after all, we’ve all heard about that for some time now). But your financial fertility is different, and it’s one of those things that can easily slip by you, without you even knowing it exists.

Let’s start at the beginning. I coined this term to describe all of the financial objectives that you want to achieve before a certain point in your life. That’s the “financial” part of the phrase. I use “fertility” to define the unfortunate reality that we only have so many years in a decade (and in our lives) to get to where we want to be from a financial perspective-and like it or not, there’s no reproductive technology when it comes to your nest egg.

Of course, everybody’s definition of stability and success is different. For some of you it will be paying off school loans, for others it will be owning an apartment of your own, and for some of you it will be finding a job and living in a way that makes you feel both challenged and fulfilled (that elusive work/life balance). But there are four basic principles- four ways to check in periodically on your overall financial health- that will help you stay on track and make the most of your twenties and thirties, no matter what your particular goals for yourself and your money may be.

1. Be An Active Participant In Your Life

Making active choices in your twenties and early thirties is the best way to get the most out of your financially fertility. While I don’t advise picking a job or a graduate program just to make more money (in fact, that’s often a recipe for unhappiness), I do tell women to be hyper-conscious of the ways in which their decisions are going to affect their financial realities.

For example, be aware that some cities have an incredibly high cost of living and some graduate degrees don’t always yield the most bang for the buck. That certainly doesn’t mean you shouldn’t pursue a PhD in Art History or that you shouldn’t move to New York for that job in publishing. But it does mean, you should make a calculated, informed financial decision before you take out student loans or load up the moving van.

2. Do Not Mistake “Investments” For Investments

Boy, if I had a dollar for every time I hear someone call a new designer handbag or hot pair of shoes “an investment piece.” Whatever you do, do not fall into the trap of mistaking an ordinary material good (no matter how lovely it may be) for a financial investment.

But if you do stash a few hundred dollars here and there (maybe from your tax refund or a holiday gift), you’ll have the power of time and compounding interest on your side- and you’ll have thousands of dollars down the road, especially if you put it away in a tax-free retirement account. So look at the $100 cashmere sweater in your hands, and then try to picture ten crisp hundred-dollar bills before you buy it.

3. Stay Off The Plastic

Without question, high interest credit card debt is the number one way to ruin your financial fertility at any age. And don’t fool yourself: a few hundred dollars here and there does add up over time, and before you know it- your credit card statements are stressing you out and holding you back.

4. Set Your Own Standards

Oh how I wish I’d really mastered this before my mid-thirties! But the secret to your financial fertility is to ignore how everybody else is spending their money. Keeping up with the Jonses (whoever they are, that girl in your office with the Chanel purse, or the couple who just renovated their kitchen with those fancy-pants appliances) is a surefire way to waste your most financially fertile decades. When it comes to your bank account- do your own thing and try to block out the consumption noise around you.

Jacoba Urist is a lawyer and family finance writer in Manhattan where she runs her own personal finance consulting practice. She has a JD and an LL.M. in Taxation from New York University School of Law. Jacoba is a regular blogger for The Huffington Post and her writing has appeared on MSN Money and The Today Show, as well as numerous other websites. Follow her on Twitter @TheHappiestPare.