How to improve my battery life on an IPhone 4S?

I got my phone about 6 months ago and the battery was fine but all of a sudden about 2 months ago my battery just kept dropping non stop even when I'm not on it. I know iPhones don't have good battery for starters but this was dropping like no tomorrow. It would have dropped 50% in 1 hours and I had been on it for like 5 minutes within that 1 hour period. Iv updated my phone, I turn my cellular off and my brightness down all the way and it doesn't work. Iv rang apple and they have done a test on it but they said everything is fine, but it's not. My phone is under warranty but apple will only do it if test says it's a glitch.

1.Lower the brightness
2.Update to the latest software
3.Use music, videos, games or internet browsing sparingly.
4.fetch data manually, or set fetch data to "hourly."
5.Turn Wi-Fi Off.
6.Turn Cellular Data and (especially) 3G off.
7.Turn off push mail when you're not using it.
8.Turn off push notifications.
9.Use location software sparingly
10.When no coverage exists, switch to airplane mode.
11.Close apps properly.
12.Give it space when it charges.
13.Lock your phone (or put it on a short auto-lock).
14.Let your phone complete at least one charge cycle each month.

For more detail you can go on this site:

http://www.brighthand.com/default.asp? EwsID=18345&news=Apple+iPhone+4S+Battery…

http://www.wikihow.com/Save-Battery-Power-on-an-iPhone

Turn off all apps that run in the background. Manually check your emails instead of having your phone do it automatically at regular intervals. Turn off the automatic update feature. Turn off Wi-Fi and Bluetooth. Turn down the brightness. Turn down the sounds.