Temperature setting - the electricity consumption of air conditioners depends on the thermostat temperature. The lower you keep the air conditioner temperature; the higher will be the electricity consumption.
Other electronic appliances in the room - All electrical appliances emit some amount of heat in the room which eventually gets cooled by the air conditioner. Even bulbs and lights emit heat along with the light. Thus if a room has a lot of lights, it will need more air conditioning - hence increasing electricity consumption.
Clogged air filters lead to higher consumption of electricity to perform regular operations. Hence cleaning dust filters regularly is highly recommended.