itotito

I won't speak for T1, because I believe they judge how much insulin to inject based on their reading

But if you are T2 and know your body well, and know how it reacts to certain foods, and are relatively consistent, you can test less often.

If you are T2 and don't know your body well, at first you should test often to learn how your body reacts. When you know, you can slow down.

I think the most important thing is to test before and after meals to understand what food does what, and depending on the time of day. Once you see a pattern, you can probably test less. This will allow you to adjust your diet.

These days I do 1 test a day and I alternate, morning, noon and night. If I see something abnormal, I may test a bit more until it gets back to normal. 1 tests consists of before and 2 hour after a meal. I don't test weekends, because I hate worrying for nothing. So I usually use about 10 strips a week.
Often I'll have a salad for lunch. I do write down my levels. I've been as geeky as to chart them.

It also depends on what I am eating for a meal. I know exactly how much a salad will raise my levels, so I don't even bother. Same things for an omelette in the morning.

I have used thousands of test strips to get to the point I can predict, most of the time, what my body will do.

A journal helped a lot to figure out. I would note what I ate, the time of day, the excercise I did......