There seems to be a growing trend for folks to write down the tank quantities and come back to it. I don't bother.
All you really need to do when you come back to it is FU+FOB - is it what you started with (within 100kgs or so for APU usage on the ground) to see whether or not you have a leak. If no leak - manage it because the ac won't manage it for you. Either open the X-Feed (if no leak) to see if that stops it going OOB or leave it, let an imbalance develop, and then run the Fuel Imbalance Procedure from the QRH to fix it. Just keep coming back to "fuel" when you have finished something or as part of your review (fuel is time).
mcdhu