One thing I found in my Genius Bar experience is that people that are anxious about their iOS device battery life are constantly checking it to see the percentage and how much it has dropped from the last time they checked it. So if you check your device twice as much, simply to check on the battery life, you are essentially halving the time your device will last.
Stop freaking out and enjoy your life. There are more important things to worry about than your device’s battery life. The control freak inside you might freak out the first few days you do this, but you’ll get used to it.
I’m a much happier person since deleting Facebook from my phone. I suspected it improved my battery life too and this article confirms it. I’m going to give turning off my battery percentage indicator a shot now.