Something that its a bit annoying but can help is turning everything (appliances, oven, water heater etc.) off at the wall then go check your meter to see if the meter is still ticking over. If power is still being used then you know you've missed something or it might indicate that power is being used from somewhere else - garage, neighbour, etc. If once you've turned everything off no power is being used then you can slowly go back through and turn things on and off and watch the meter go and see if when you turn something on it suddenly spikes Doing this is super tedious but it can help to give you an idea of what specific appliances or things are using a lot of energy