4. Making vacation reservations

When you call to reserve a hotel room or rental car (or in some cases, to make a dinner reservation), one of the first things they’ll ask for is a credit card number. Depending on the company’s policy, it may use the number to charge a cancellation fee or security deposit, or simply ask you to hand over the number as an act of good faith. But no matter what the policy, things go more smoothly if you use a credit card.

This isn’t to say that you’ll never be able to make a reservation without a card. If you’re really determined, like this woman who spent six years living without credit, you can usually make a reservation with a debit card by calling with plenty of lead time and asking how your destination can help make things work.

5. Earning miles, points and cash back

If you haven’t started using cards that reward your spending with airline miles, points or cash back, you’ve missed the boat.

No matter how your credit card rewards you, the systems generally work the same. For every amount you spend, you’re given cash or credit that you can redeem for some sort of reward, such as a plane ticket or a night's stay at a hotel.

Before signing up for a rewards card, you’ll want to compare your options to see which is the best fit, based on your goals and spending habits. Sites such as Credit.com and Credit Karma can help with that.

And of course, this isn’t an excuse to overspend in pursuit of a few points. But look at it this way: If you’re going to spend money on your credit card anyway, you might as well be rewarded for it.

6. Emergencies

Ideally, you’d have a complete emergency fund with at least six months of net income stored in a savings account to be used if -- and only if -- you lose your job, have a medical or dental emergency, suddenly need a major home repair, or if your car breaks down and you’re without your primary form of transportation. Here’s a handy guide to what really counts as a financial emergency.

But if your emergency fund doesn't quite measure up, or you’re stuck without immediate access to that account, a credit card can fill in the gap. Cover your costs with a credit card when disaster strikes, then pay the bill using the funds set aside specifically for that purpose.

Click here to become a fan of MSN Money on Facebook

More from LearnVest: