We actually don't spend that much money each month because we don't go out like for nights out or that every week since neither of us drink it would be a bit boring and pointless we do go out for meals and days out though.
So we always have a good amount of money left each month and it all just stays in the bank and builds up.
Other than that we have a separate savings account for emergencies and that and we normally put maybe about £30/£50 a week into that, I dip into it a lot when I want to do some shopping though