There are credit cards that give you 2% cash back.
This means that every purchase you make, from anywhere, has a 2% discount.
If you buy $200 on Christmas presents using cash or a debit card, that's four $1 bills that you just ripped up and threw in the toilet.
Here's a credit card crash course:
Most mileage cards aren't for you. Unless you fly every month, you're getting screwed.