We do not have a budget so nothing is set in concrete, but DH keeps $500 a month in his personal account (he is paid monthly) but he rarely uses it so most of it goes into the mortgage/addiional savings.
I keep all of my fornightly wage and out of this comes daycare ($400) and the rest is mine to do what I want with (around $1300). I don't use much of it but the types of things it is used for are clothes for me and DS, the odd lunch/meal out, haircuts, personal training, my garage sale addiction, anything I buy for myself and if I go to the supermarket groceries as I hate touching the joint account.
Generally mine just adds up and we then use it for spontaneous holidays, eg next week we go to Bali and the cost is coming out of my account so we don't even notice the money gone.
Before DH a partner and I used to have $50.00 a week and this worked really well as I hated how much alcohol/computer games he would buy, but once it was his personal money and not joint I did not worry about it (at least from a financial point of view) as it was his cash to spend as he pleased.