Since I don't get to the range as much as I should, my carry ammo gets changed every time I go to the range (~quarterly). I start range trips, by going cold right out of the holster to running a Bill Drill or FAST a few times. Once the ammo in my gun and the ammo in my spare magazine(s) is depleted. I switch over to other drills and practice ammo.
At the end, I load fresh carry ammo from my same lot numbered stash - or if I have to switch to a new lot number (same ammo type, e.g., 147-grain HST) I'll fire a random selection of 5-rounds from each box in the new lot number to confirm nothing seems odd and load the remaining ammo in my gun and spare mag(s). I, honestly, think that this last step is overkill, but it makes my OCD happy, so I do it. I try to buy five boxes of carry ammo at a time from the same lot number.