Always relying on cellular data
Some people think that turning Wi-Fi off will improve battery life. That’s a myth. Turning the wireless setting off can actually worsen battery life on your iPhone. The amount of Wi-Fi power taken to communicate with Wi-Fi base stations is minimal and way lesser than what using data will do to drain your battery in a jiffy.
Do this instead: Simple. Whenever possible, use internet Wi-Fi. Under Settings, make sure Wi-Fi is switched on, and leech onto a Wi-Fi source as much as possible.
More after the break...
Not using Airplane Mode enough
That little airplane icon is underused. Leaving your phone on Wi-Fi when you know you’re definitely not going to get any complimentary connectivity means your phone has to work harder to communicate, at the expense of your iPhone’s battery life.
Do this instead: At infamous dead zones with zero coverage or when you’re overseas, turn on Airplane Mode. You can get to it right from Control Centre by swiping up from wherever you are on your iPhone without having to weave your way around the workings of your iPhone. Otherwise, access it from Settings, then Airplane Mode.