Those with CFRD, how are you deciding how much insulin to take?

What I've been doing that seems to work for me is plug in what I'm going to eat into Nutritionix, get a rough estimate of the carbs, and cross reference that carb number to about how many units of Humalog it takes me to not spike or go too low on prior days. On days where I'm eating a repeat meal, I scroll back through my meals, find the meal, and cross reference the meal time with the Libre numbers to find how many units I took and if it was in the ballpark. Timing also seems to matter for me, for example, a ham and cheese croissant with a grande cafe latte requires about 6 units of humalog in the morning vs say 3 or 4 to consume the same thing in the evening.

I used to also plug in the carb number into the Libre app, but I stopped doing that a few months ago when I realized the meal contents mattered (pasta vs a sugary beverage), which the Libre app doesn't seem to have a great way to track.

It's tedious, but it works. Is there something that you're doing that is less tedious and still effective?