I've gotten used to using my phone with low luminosity. That, more than anything has propelled me from barely making my day, to having enough juice for 15~18 hours, even with a phone endowed with a less than stellar battery.
Also, as one gets familiar with a phone, one adds a bevy of apps and widgets, and these eventually add-up. Together, they they cause a slow but steady increase in battery drain, mostly caused by background online data fetching. Use your app manager in the settings and configuration applet to kill all unused apps, just clear cache and force stop the apps. Use of news reader software is often a big power sucker. I've ditched Flipboard, Mobo reader, Feedly etc... I've gone back to using good old bookmarks, and my browser. Less convenient ? Somewhat, because I have to check my websites one by one for new content, but, my browser does not needlessly pre-load tons of data, it does not check and re-check web content needlessly, so I'm saving big on radio use for data, thus saving power.
If your not convinced of this constant activity, I suggest you download
Bandwidth monitor, you will be suprized by how much activity goes on. it seems like everything on Android calls home, even when it theoretically should not need to.
Setting your screen time out for a very short period also helps, and using a BlueTooth earpiece should also augment battery time. I believe the sound amplification is harder on battery than the BlueTooth radio is. Perhaps this is not true of all phones, but it has been so far on most devices I've dealt with.