Turn off Background App Refresh
Another example of phones trying to be helpful at the cost of battery power is when apps run or regularly refresh their data, even when you aren't actively using them. Disabling this feature is complex to the point of being pointless in Android – as of right now you have to either install a Task Manager app, which are of dubious function and value, or else find the list of currently running apps in your settings, and quit the ones that appear to be using battery life. But you'll have to return to that menu again and again.
iOS happens to make this process easier, with a Background App Refresh screen (under the General menu in Settings) that lets you turn off background refreshing for all apps, or individual ones. As with location services, you'll likely find only a few apps that should be updating their data on a constant basis.