Is your watch running 5.0? The battery life made a quantum jump from then to now. Also, if you're running a pre-5.0 watchface, versus a current one, that might make a difference. (They changed all the APIs around. The new ones at least are a whole lot easier to work with...)

Fitness stuff: I've blocked all the notifications from the fitness apps, and it wouldn't surprise me if that helped my battery life. There really isn't any other way to disable things unless you want to play games with adb to uninstall the APKs, and that might well break things.

FYI, last night when I put the watch on the charger, it had been been running 13 hours and the Wear app on my phone estimated it had 17 hours left. So 30 estimated hours total. Not bad. Today, it's been off the charger for 5 hours so far and the app estimates 23 hours left. So 28 hours estimated total. I can totally live with that.