When most people think about financial decisions they make during their lifetime, there are a few that should be on the list but probably aren't.

That's because the many important decisions we make that have a large financial impact are made with money as a secondary concern. Here are four life decisions in which you can either save a fortune or end up digging yourself into debt so deep, you could spend more than a decade trying to remedy the situation.

College: Most kids graduating from high school and heading off to college have no idea they are making one of the biggest financial decision of their life. Cost usually is not a concern -- how to find loans are.

While it's possible to graduate from college debt-free, it's even easier to leave school with tens of thousands of dollars in loans.

Graduating without loans allows you to enter the workforce and immediately put aside a small amount of your paycheck toward retirement when it's most valuable to do so. Those with college debt will spend a decade or more paying back the loans with interest instead of earning the interest for themselves.

Wedding: Weddings are supposed to be about love and romance, but they are also a good indicator of how your finances are going to end up during your married life. The best financial decision you can make is to skip the wedding altogether and put the estimated cost toward your retirement fund.

If eloping isn't an option, you will either create a wedding budget and pay for it in full or end up going into debt to fund it. While having the wedding completely paid for won't give you the head start that eloping will, it will still be much better than if you finance the big day with loans.

The way you handle money for the wedding will be a good indicator of how you and your spouse will end up managing money together. Going into a partnership debt-free makes it easier to reach your mutual goals than if you start day one in debt and continue to build on it.