Display
Display brightness is an important factor in battery life.The more brighter the screen is,the more juice it drains.So keep the brightness under control.Using automated brightness is not adviceable.Try manually adjusting the screen brightness.
Cell Network
This is simple stuff,but results in noticeable improvement in battery life.Toggle LTE/3G to 2G while not in use.(While on WiFi).You can use Smart Network to switch between networks.
For devices that support Fast Dormancy(Read Here) can disable it to save some juice on 3G.(Link to disable Fast Dormancy for Xperia Devices)