How to make iPhone 5 battery last longer?

I'm going on an 18 hour school trip to an amusement park on Saturday and I want to make my iPhone 5 battery last as long as possible.
Just to give you an idea of what my planned phone usage will be: about 2 hours on the way (mostly music), emergency use only at the park (as in to contact adults if needed) about an hour and a half on the way back (Mostly music) and I need to be able to call my parents when we get back.

I know it doesn't seem like a lot but for some reason my battery drains very quickly. I was going to let my phone completely die out the night before and charge it overnight. Any other tips?

Turn off your brightness and bluetooth.put your phone on vibrate too

Turn your Wi-Fi off turn the brightness all the way down keep your phone off until you get on the bus and it starts to leave while your listening to music keep your phone standby and restrain urself from turning on the screen turn off while your at the park and ask workers and use clocks if you need the time and then turn back on your phone when you get back on the bus

The brightness takes a toll on the screen, tone it down so that your battery would last longer.