a。Reduce the of your display. (Settings » Sound & Display » Brightness）
把亮度调低是比较重要的一步。
b。If your device has an AMOLED screen, always use a black background. AMOLED screens can reduce power usage sevenfold by displaying black instead of white or any other color. When searching on your phone you can also use Black Google Mobile at bGoog.com to get standard Google results (including images) all in black
至于其他方面，比如关掉wifi，GPS等等，往往都是干扰使用的地方，没有什么值得采取动作。。。。