If you are someone who travels a lot or maybe wants to go somewhere soon, I would suggest getting a credit card that you can start accruing miles on.
If you already have a credit card, make sure it is one that you can accrue miles on! I believe it is the key to traveling! I am not telling you to get a credit card if you don’t already have one, because they can be dangerous.
Depending on which card you have there are a lot of benefits (miles for flights/hotels, airport club access, GOES, etc). Yes, you do spend the money to get the miles, but it is nice to travel somewhere on miles and feel like you save money.
Just a tip, I personally feel you should have one that accrues points on all airlines. If you get one that is specific to just one airline, finding a mileage flight can be limiting.
If you want any suggestions or more information on how I book all our flights I am happy to do a post that goes into more details.