All money goes into one pot and is family money. Out of that we pay for everything.
(I say one pot, obviously we have various bank accounts, some in joint names, some like ISAs in individual names, but we consider it all to be joint money)
We do not have our own spending allowance.
We both have a similar attitude towards money, and so we just spend as we wish from the joint pot because we both know incomings and outgoings.
We don't question each other about occasional coffees, beers, nights out, clothes, or purchases such as books.
If we are planning something big but individual, such as a hen night or mates holiday we discuss it like grown ups and see if we can afford it. (And sometimes that may depend on who has done what recently).
Our way wouldn't work if we thought differently about money, eg one a big spender and one extremely frugal.
It also wouldn't work if one of us was oblivious to family needs (eg that £400 in the account in June is not holiday spending, it school uniform buying money.)