You'll want to check the buds not the leaves.
Sup Mr. Head? Thanks for stopping by.
I read through this when researching about it. I copied and pasted the meat and potatoes below:
"The best way to check how the trichomes on your plant are doing is by means of a loupe or a microscope.
I would recommend getting ones that can at least go to 60x magnification.
Getting one that can go to 100x would be even better, but the more magnification the more cost.
All you have to do is take a small sample of a leaf with trichomes on it, or if you have a loupe or a USB microscope simply look at the trichomes on the plant to determine their 'state'.
It's important that you check all over the plant, since trichomes will usually develop and produce faster at the top(s) of branches and slower and the bottom of the plant.
Some people choose to harvest the tops first and let the bottom nugs grow a bit more to let the trichomes mature and develop further but also to let the buds fatten up more. It's a judgement and preference call really."
It seems like I will eventually get to the buds.