Did a full discharge about a week into my iPhone 6 ownership. Drained it till dead and let it rest a bit. Then charged to full and a bit more, took it off the charger and reset the phone (Home + Power button for 10sec). Only reason I did this was because my battery gauge was wonky before that - it would stay at a certain level for a long time and suddenly drop maybe 5% just like that. The battery life seemed fine enough, just the readings were a bit skitzo.
Haven't had the issue since I performed the above-stated procedure, though sometimes it does seem to drop 2% instead on 1%. No biggie.
Other than that, I just charge whenever I need to. I get home from work/play with about 30% - 40% usually. Put it on the charging dock and go do homely stuff for a few hours. Take it off the charger before bed. Done.