Help

Does anyone have any suggestions on how to save on the power bill.
My house is total electric, and with 3 teenagers living in the house I am constantly
following them around turning off lights and unplugging stuff.
But with all I try to do my power bill is running $300.00 a month, sometimes more.
I am at my wits ends, I cant keep it up.
SO if anyone has found helpful tips to keep the bills down, Please pass them on!

Thanks