How to make my iPhone 5 battery last all day?

I'm leaving from the beach to Disney tomorrow and it's a 2 hour drive there and back in one day. And I'll be in Disney all day long so I want to conserve my battery life. I wanna still text my girlfriend so how so I make up for that battery loss?

Lower the brightness all the way and turn off all apps when you're done using them. If you don't know how to turn off the apps just click the home button twice then flick up the images of all the apps you're not using