We had always asked ourselves that question too (so where the money goes).
I can only advise you (I think I wrote this in another thread once): Take the bank statements from 2011, a couple of cups of coffee, and half a day.
Open a spreadsheet and get started.
Go through each statement.
Record everything that goes out monthly with amounts.
Record everything that goes out quarterly / half-yearly / yearly converted to the month (so divided by 4 / 6 or 12).
When you have gone through all the statements, you should have recorded all fixed costs (including GEZ, taxes, .....).
Then you can see where the money goes at first.
What also helped us more or less was a "household cash box."
Even if we didn’t have to watch what went on food from it, it clearly shows where the money goes.
So just plan an amount x for groceries and keep it at home in cash. Then really pay for the shopping consistently from it.
For us, the difference was simply that we saw how the money decreased. That was not the case before (when you paid by card).
Once you have found the right amount x for yourself, add that to the list.
Also add what you spend, for example, on fuel every month.
Now actually nothing should be missing except "leisure expenses" (so for example we go out for food / drinks in the evening).
Now you already know what you spend per month. And only when you see the individual items can you, I think, also cut / eliminate unnecessary things.