If you are unfamiliar with Google Flights in its original form, you should know that you have two main options for finding flights.
There is a world map that you can click on to explore prices around the globe for certain dates you select.
You could also do the reverse of that and select where you want to go and when. You can filter flights under the date fields to match your preferences, for example if you prefer nonstop flights. Google Flights will then show you the available flights based on your search, with the best cheap flights appearing first. Alternatively you can choose to have flights sorted by departure, arrival, airline, etc.
Google Flights will also let you know if you can fly cheaper by changing your dates. As you can see below, I could save $57 by moving my trip around. If your travel dates are flexible, this is super helpful.
Discover Trips Tool
When you first open Google Flights, you will see under the normal search fields that there is a Discover destinations module. When you click one of the bubbles (you will see a few months listed and a few trip lengths) this module will change to Discover trips.
Here is where the flexibility and fun begin as you can select a month, the approximate duration of your stay (weekend, one week, two weeks) what area of the world interests you (e.g. South America, Caribbean, Middle East), and/or what you would like to do on your trip (e.g. Beach, Shopping, Ecotourism, Culture).
Once you select these four fields, Google will crawl all flights that fit those categories and show you a plethora of options. In the example below, I said I wanted to go to South America to experience some Culture for one week in May. Google came back and gave me nine options (six pictured below) that I can click and browse to see what flights they are quoting at that price. From there, if they are less than ideal dates or times, I can use the basics I outlined above to shift around my dates for that location and sometimes even find times that are better for the same (or similar) price.
Finding What Works For You
In my example above, those all seem like pretty great prices but in some cases, it could be a Saturday departure with a Saturday return (not ideal for maximizing vacation days) or a flight with multiple stops (more work than vacation). To narrow down your search, click on the result that most interests you to take a closer look at the flights offered. You should be able to tell if their recommendation isn't aligned with what you're looking for. For example, in one of my searches I discovered most of my options were one-stop flights on an airline I've had bad experiences with. To eliminate that airline I changed my filter to nonstop and not only found a nonstop flight on a better airline but it was only $46 more than the original one-stop.
Booking Cheap Flights with Google Flights
Once you select a flight, you can book, save or share your itinerary. I hope this introduction helps you find your next travel destination, as it helped me find a great deal to Athens randomly when I was messing around with the awesome trips tool. You never know, the more you use it and ponder about where to go next, you too could find an amazing deal to somewhere you only dreamed of going before.