I have been a big proponent of what I call "common sense green".  I hate to see people do things for the sake of being green - but are not really green at all.  Anyway I came across some useful information on the fine homebuilding blog regarding some green "myths".  The article identifies a number of common strategies that do not necessarily save you much energy.  Those include the following:
- furnace tune ups
 - sizing furnace correctly (not oversizing)
 - basement duct sealing
 - floor insulation
 - caulking and weatherstripping
 - window replacements
 - tankless gas water heaters
 - cooling your attic
 - changing furnace filters monthly
 - opening your refrigerator quickly
 - using drapes to insulate windows
 
You should read the entire article if you want further information.  See the following link:
http://www.finehomebuilding.com/item/8954/how-not-to-save-energy