So after installing iOS 7 and playing around with it, I noticed that the battery was draining slightly faster than usual. What became apparent was that I saw the location icon on the top right (next to the battery) a lot more often than I did on iOS 6. And as we all know, GPS (or any location service) drains your battery like crazy. So I found what caused it for me on my iPhone 5.
First, if you haven't turned on the Status Bar Icon, go to:
Settings > Privacy > Location Services > System services
And switch on the Status Bar Icon (it's located at the very bottom).
Now on the same screen disable anything you don't need. This is how it looks for me:
On this screen there are two new options in comparison to iOS 6: Wi-Fi Networking and Frequent Locations. Especially Wi-Fi Networking seems to check for your location very often. I turned off both new options.
One other app that seems to check your location a lot is the new Weather app. So if you go to:
Settings > Privacy > Location Services
Just turn Weather off.
Of course all the other known ways like turning off 3G/LTE when you are on Wi-Fi, turning off Bluetooth, turning off push for email addresses that don't need it, etc, will always help a lot.
First, if you haven't turned on the Status Bar Icon, go to:
Settings > Privacy > Location Services > System services
And switch on the Status Bar Icon (it's located at the very bottom).
Now on the same screen disable anything you don't need. This is how it looks for me:

On this screen there are two new options in comparison to iOS 6: Wi-Fi Networking and Frequent Locations. Especially Wi-Fi Networking seems to check for your location very often. I turned off both new options.
One other app that seems to check your location a lot is the new Weather app. So if you go to:
Settings > Privacy > Location Services
Just turn Weather off.
Of course all the other known ways like turning off 3G/LTE when you are on Wi-Fi, turning off Bluetooth, turning off push for email addresses that don't need it, etc, will always help a lot.