Like others have said as long as you are consistent. I test once I'm up and ready for breakfast, as I need help to get up sometimes this will be 5 in the morning before my beloved leaves for work, other days it will be 7.30 after my carer has got me up and sorted. Then I test again two hours after breakfast, then before and two hours after each meal. I record what the results are and what I've eaten as I find that after 3 and a half years of T2 something that I've always had will suddenly spike my BG so I know to avoid it for a while and then try again after a week or so.
Hope all of the answers have helped