How to get my iPhone battery to last longer?

My battery seems to die around 4 pm if I stop charging it at 7 am. (Have to go to school… ) how do I get it to last longer? Maybe to 6-7ish pm? I listen to music ALOT if that does any damage, and in school, I only get 1-2 bars.

There's a whole load of 'hidden' options you can turn off which significantly improve battery, do all of these;

Go to Privacy > Location Services > System services (at the bottom) and turn off everything in there. (You don't NEED any of those, but you can enable them if you need any)

Go to Mail, Contacts, Calendars (on the main settings page) > Scroll to the bottom and turn off 'Shared calendar alerts' and 'New Invitation Alerts'

Remove any apps you aren't using from push notifications by going to Notifications (on the main settings page) and turning off the apps you don't need notifications for. Make sure they're fully off, by tapping the name of the app and sliding EVERYTHING in there to off, otherwise it will continue using battery.

Go to General > Siri and turn off 'Raise to Speak' or turn off Siri altogether.

If you don't use FaceTime/iMessage; turn them off.
FaceTime: Go to Settings > FaceTime > and slide it to OFF.
iMessage: Go to Settings > Messages > slide 'iMessage' to OFF.

Go to Settings > Photos & Camera > and turn off 'Shared Photo Streams' unless you're using them.

Go to Settings > iTunes & App Stores > Turn off the switches in the 'Automatic Downloads' section unless you're using them

Go to Settings > Music > ensure 'Shake to Shuffle' and 'EQ' are both OFF. You could also sign out of Home Sharing, if you don't use it and you're currently logged in.

General (and perhaps obvious) tips;

Ensure bluetooth and personal hotspot are off when not in use. You may also consider turning off Wi-Fi and cellular when not in use.
Lower the brightness of your screen by as much as possible.

I hope I helped, even if you only do a few of these, you'll probably notice an improvement in battery life.