simple things like wearing caps and sunglasses etc that you may accept the fact that they sit under your ear seal, i wear wire frame sunnies like the Mako,s and have them clipped short to avoid them effecting the rear of the seal as well and nudge the cap up a little and found this doubled my batt life.
It was always recommended not to use rechargables but being a bit of a rouge i did, i use 250 MAH and get 3 days or more.