Keep on the lookout for battery-hungry apps
As much as we wish that every app out there was written to be a great phone citizen and be cautious in its use of your phone's limited resources, this unfortunately isn't the case. If you have a bunch of apps installed and find your phone's battery is draining faster than you'd like, you can take a look in the phone's settings to try and diagnose what's going on.
Head into the phone's settings, tap Battery and then Battery usage. This isn't a definitive list of apps that are using up your battery, and of course if you actually use an app a lot it'll show up, but the battery usage screen can point out if something is chewing up your battery without your knowledge. If you find an app that's consistently misbehaving, consider uninstalling it.