No custom kernel, just a straight up stock SF with VZW bloatware removed. I only auto-sync my google account. Brightness stays at about 30-40%. Haptic feedback OFF. BW weather clock on the home screen and a couple toggles for vibrate/silent are my only widgets. No over or underclocking, my phone is bone stock, minus the bloatware.
I typically spend 2-3 hours phone time, 20-30 emails, a least 2 dozen texts, anywhere from 2-6 hours of MP3 streaming or playing - and I went to bed last night after my phone was on for 14 hours at 80% full. No that is not a joke. Widgets, AutoSync, brightness, and constantly having the screen on will KILL YOUR BATTERY. Keep GPS and Wifi off unless you are actively using them - Google locations is more than fine for casual lookups and location awareness.
Last week when the phone was new I ran music for 8 HOURS with the screen off - it had virtually no impact on battery life. One thing I've noticed, if you use speakerphone, make sure to turn off the screen with the power button or that will suck you battery dry in a matter of minutes!
I don't feel like I'm "compromising" my smart phone at all, just using some SOP when it comes to keeping smart phones juiced up.