What to look for in a travel rewards credit card

Travel costs can really add up. One way to keep expenses down: travel rewards credit cards.

A new study from Nerd Wallet says Americans are missing out on about $22 billion per year in free travel.

How do you benefit from using credit card points to travel?

I tracked down points expert Summer Hull, the woman behind mommypoints.com, to give us tips.

"When you're looking for the right card, you want to look for a few things. One, you want a big sign-up bonus. You can get up to $1,000 when you hit the spending requirement," said Hull.

For example, I found a deal for a Delta Skymiles card. Just for signing up and spending $1,000 in three months, I got 60,000 points. That's $600 of free miles that I used to fly to Los Angeles.

When you sign up for these cards, use them to pay for things you're already spending money on.

"Swipe your purchases on your card from your car insurance, groceries, daycare, and then turn that into miles to travel the world without using cash," said Hull.

But make sure you're not going into debt for points.

"The biggest way we use credit cards in my family is that we treat it like a debit card. It's a credit card, but every month we pay it off," said Hull.

If you do end up paying interest on a rewards credit card from remaining balances, then the rewards you're earning probably aren't worth the interest you're paying.

Also, make sure to look out for annual fees.

If you want to avoid credit cards all together, Hull has a tip for you.

"There are prepaid products that earn miles. A new one is a Mileage Plus Go Card. It's a prepaid card so you owe on it what you want and then you can earn one mile per dollar spent on that card up to 30,000 miles per year," said Hull.

The Mileage Plus Go Card does have a free plan or you can pay $85 per year to earn one point per every dollar you spend.