Tired of constantly being pushed out of the way by customers after me in a line, I now have a new technique for how I pay for my goods at the grocery store. This works as well (sometimes) in the bakery. Before: I would pay for my groceries and then scramble to put them in the bags. This was not efficient because after I paid, the clerk would begin scanning the next customer's groceries and push them off the scanner. My groceries would then begin to be mixed up with the other customers. The other customer always (being French) would have begun packing their groceries on top of mine and thus reaching over me, standing too close to me, moving me and my groceries out of the way.
Now: I let the cashier scan all my items and I begin (when I am ready) to put my groceries in my bags. I don't bring out my wallet until I've packed all my items. Then I bring out my wallet and pay. Now I get to pack my groceries with no rush (well, other than all the other customers huffing and puffing down the line) and pay without being frazzled.
N.B. Sometimes this doesn't work at the bakery where if I'm too slow getting my money out (which seems to be the usual case) the baker will take the next customer's order and their money before me, which seems to be confusing two orders at once, but apparently the French bakers are a very efficient lot and can handle several orders and multiple money exchanges at once. (Except for the times when they get my orders wrong!)