Is they're and order in which some do the parameters? I mean if I'm checking a reef or fish only tank and the nitrates are high, do I continue checking the rest or go ahead and change the water then recheck after that?
I test all parameters (that were planned) and only than make changes to the chemistry if needed.
If there is anything I should follow up, I would do so the next day.
I also make sure to always test within the same time range, and for nutrients specifically - between 6 to 8 hours after last feeding (or any nutrient related dosing).