1.Drop the screen brightness
One of the easiest ways to improve battery life on the iPhone is to drop the screen brightness.
2.Auto-Lock the screen
One of the important tips for saving your battery is to lock the screen after a short interval.That help you to conserve the battery life because it turn the screen off when your iPhone is not in use.
3.Selectively turn off/on radios
If you don’t need WiFi or Bluetooth or 3G, turn off the radios.
One of the revamped feature in iOS 5 is Notification,that notify you what's happening on but that consumes great battery.Disable notification for any apps that you don’t care about by clicking on the individual apps and switching off Notification Center.
iPhone bought lots of location features but these features have negative effect on battery life.
Disable the whole lot, or selectively enable it for a specific set of apps.the more your apps can use location that consumes more battery.
6.Turn Off Siri's
Many iPhone 4S owners have reported that "Raise to Speak," a Siri function that allows users to lift the phone to their ears to activate Siri, is causing battery drain. Unless you use it often, turn it off.
7.Don’t go to the cloud
Turn off the icloud syncing when you are not using it because it's take lots of jucie too.