Turn off gps and BT, and only turn em on when beeded. Using wifi wherever possible is the key! The problem is, on stock and other custom non-ics roms, when you connect to wifi, it disconnects the 3g/4g radio, but doesnt turn it off.....hence defeating the purpose.
I always leave my wifi radio on. and I made a simple rule in tasker.....if wifi connected, disable radio. On disconnect, enable radio. and thats it. Ull have full data, phone calls, and SMS. MMS will come thru, but ull have to go to 3g/4g to fully download it.
For me, I have wifi at home, work, and at gym. I can get a good 30 hours with the right mix and normal use. (standard battery).