The biggest cause of energy consumption is your AC or heating unit. If it's not working properly, it can cause huge spikes in usage and cost. Leaky faucets or pipes can also can cause consumption increases by wasting water.
Make sure to regularly check that your pipes and appliances are in good working condition. If you have found an issue or are just not sure, we suggest that you contact your landlord or your residence maintenance staff in order to have them check it out for you.
For more tips on how to reduce your electricity usage, read this guide:
10 Ways To Reduce Your Electricity Usage