To the south of the house plant trees which lose their leaves in winter and shade the house in summer. If repainting, chose white - it doesn't fade. Buying an airless sprayer for jobs like this can pay for itself in the long run. Put in double windows with a high R-value when replacing. Buy a carpet machine for rugs, furniture, and car upholstery rather than renting one every year.
Utilities Look for an insulated apt. or house.
Heavy duty door closers on exterior doors keep the heat inside in winter and outside in summer, and they prevent slamming. Turn off the furnace pilot light over the summer. Hook up the washer only to cold water. Wash only full loads. Dry only full, consecutive loads.