No Short Program
You might think a shorter program will be cheaper because the washing machine is on for a shorter period of time. This is not true, because short programs consume more energy as the machine will automatically raise the temperature to compensate for the shorter washing time.
Drying
Do you usually use a dryer to dry your laundry? Then be smart to use a washing machine that produces excellent drying results. The washing machine will use more energy because of this, but drying very wet clothes in the dryer requires more energy. Want to make it much cheaper? Then drying your laundry on a drying rack is the best solution.