Shower only when you stink, else if can, go office and shower (if got shower facilities.) Charge whatever batteries at office whenever possible (a lot doing that, haha!) Get a tv recorder, playback during weekend day time as to save lights. Fast forward to save watching time, 15 mins could be shaved off.
All above is what I could think of and can need not apply to anyone of you. ;p
Thanks for your great ideas. To add on, you can go to your friends' condo pools to swim, bathe and shower. Save water bills, pool entrance or club membership.