Optimising iOS Battery Life

1. Turn off Frequent Locations

Your iPhone wants to learn the places you often visit to give you "provide useful location-related information." This is takes up a lot of battery life and may also make you feel uncomfortable privacy-wise. To disable it go to Settings > Privacy > Location Services. There, scroll all the way to the bottom and hit System Services. There you can also turn off Location Based iAds (ads from Apple based on your frequent locations). Then go to Frequent Locations and turn that off, too.

2. Turn off the Parallax Effect

Whilst it is fun to watch - and may even make you dizzy - it's certainly not critical to running your iPhone.

3. Turn off Bluetooth

Another thing your can do is turn off Bluetooth when it's not being used.