My electricity is only 500-600 KW per month

This is how I achieve this:
1) For lights that needs to be on a long time, use only the Compact Fluorescent bulb, I noticed about 20% reduction after they are changed.

2) In the summer when running the central air con, only drop the temperature by 2-3 degree compared to the outside temperature, the key is to use it to lower the humidity level but not the absolute temperature, the humidity is what makes one uncomfortable.

3) Do not run more than one fridge or freezer, some people buy a lot of food and need the extra fridge for storage. It is very wasteful of electricity, the food is not fresh and it probably cost more than the saving in bulk buying. I have 2 additional fridges in the basement, but they are kept off most of the time, and used only when needed such as when entertaining or harvesting from the garden,

My 2 cents on energy conservation is to live with the environment, not to force it, that means do not try to set the house ambient temperature to say 20 in the summer and winter. That wastes a lot of energy to change then maintain the desired temperature all to keep very few bodies warm or cold. Live and enjoy the winter and summer.