NEW York ( CreditDonkey) — To an outsider, Millennials may seem to be on top of their financial game: Gen Y has the fewest number of credit cards and lowest average balance on those cards.

So far so good, right?

But Millennials also have the lowest credit scores of any generation, and many within this cohort tend to be late on their payments. There are a few age-related reasons for that, like having a shorter credit history, but there are also things that Gen Y could be doing better. For example, many Millennials have lower credit limits and max out their cards, which actually hurts one's score more than simply obtaining a higher limit.

With unemployment and financial uncertainty as high as they are, but it'd be a shame to let the economy get the best of our credit scores. That's why we've compiled some of the biggest mistakes people make when it comes to credit cards.

Others have fallen into these traps, so you don't have to.

Missing a Due Date

This may go without saying, but one of the worst ways to bungle your credit is to miss a deadline on your bill. There are a few reasons. First, late payments can seriously injure your credit score. Second, the amount you actually have to pay will skyrocket once the interest starts to stack up. Third, if you missed the due date because you were busy scraping together the money to pay your bill, then missing the deadline could spark a vicious cycle of scrambling to catch up. Stop that cycle before it starts by paying every month, on time.

Tapping Into Too Much of Your Credit Limit

One of the components of your credit score is your "credit utilization ratio," or how much of your available credit you actually use. This ratio is calculated across all your cards, so if you have five cards with a $1,000 limit apiece, your total limit is $5,000.

If you spend $2,500 of a total $5,000 limit, your credit utilization ratio is 50%. Ideally, you should aim to keep your usage under 30% if possible.

Closing a Bunch of Credit Cards

If spending too much on your credit cards is bogging you down, it may seem intuitive that closing out your cards and vowing to be more responsible should be a good thing. But alas, everything in moderation. Canceling your cards will hurt your credit utilization rate by lowering your total available credit, so don't jump to cancel a bunch of cards at once.

Part of your credit score is based on the length of your credit history, and that's calculated by averaging the length of each of your lines of credit. As a result, your oldest credit card is one of your most valuable. If you close that account, your length of credit will decrease and hurt your score.