Stuff I do:
1) Turn on ART. HUGE Idle battery saver.
2) Turn off "OK Google" responce. Huge battery drain.
3) Leave it on 3G when not using the internet. Even with a good signal, 4G drains the battery more, and what's the point if you're not using it. (Note, this would be easier of someone made a widget that made it easy, so I understand not wanting to do it).
4) Set the GPS to battery saving when not in use. For everything short of driving directions, that's good enough.
5) Space out any automated data synchs. Do you really need a facebook and email update within minutes of it happening? Do you even need your email auto-synched at all? (I have them all set to on demand, which takes a whole 30-60 seconds extra load time to pull down, even on 3G).
6) Turn off Google Now (I don't have it off, and I get amazing battery life out of the N5).
7) Set screen brightness to auto. Screen is the biggest battery suck, only so much you can do here.
8) Enable dark mode for any apps you can, and set your background to a non-live dark background. (Bright/lighter colors suck more battery. It's minor, but it does help).
9) Install Greenify (if you have root), and let it suspend any apps you know you don't need and don't want to take over in the background (Many games can "stick" open and running).
10) Use Wifi, have all your updates/backups that are automated happen on wifi only. Turn off Wifi (and BT) when not in use.