Let's start from the top:
Airplane mode will considerably reduce battery drain but is not advised. Airplanes mode cuts off all signals going in and out of he phone. You won't be able to call, text or browse the web when airplane mode is enabled. This is only to be used when you really need to spare that last few percents.
When you aren't connected to a wifi hotspot your phone will ping continuously until it connects again. Whenever you aren't connected to your local wifi or a public setup, turn your wifi to "Off". Then turn it back on when at a hotspot. This will save a considerable amount of battery.
Bluetooth, unless you usually have a bluetooth cellular device, is almost useless. It has minimal support for games such as Call of Duty Zombies, and Tank War- Bluetooth Battle. But other wise it should be turned off. This will save your battery alot!
Notifications, common to misconseption, usually won't affect your battery life. So enable any that you want.
In the general section, there is really only one thing to make sure of. In the Siri portion, make sure the "Raise to Speak" is off. Otherwise, your phone will die REALLY QUICK. It will scan for your head constantly.
Head out of the general tab now. The brightness and wallpaper tab is the most important. If you keep your brightness at half or more, your phone will die much quicker. 1/4 or minimum brightness is probably your best bet to keep your phone alive. Oh, and have "Auto- Brightness" off.
Other assorted options may slightly decrease power usage, but they will vary depending on your phone and apps.
Note: Using very large apps will make your phone die faster so to really keep it alive, minimize usage of those.
