Iphone 3gs battery tweaks that really work?

Hi am using a 3gs with ios6 please send me a steps to help extend battery. It is ok if i have to re-do all the procedure all over i may have missed a few set ups along the way.

Another question is it normal that even on standby you see the battery percentage drain every hour?
and i can't seem to find the compass calibration?

Please help, I just want to use some features without worrying about the battery drain.

My battery will slowly go down when not in use, but not much