Checking trichomes

I have a lab microscope and enjoy looking at the leaves on the growing plants and I noticed that the trichs on the back sides of leaves are much denser and better formed than those on the front sides.
Does it make any difference when checking on the trichs whether to look on the tops or the bottoms of leaves to determine their stage?

go top, center and bottom for a full round idea. i really just wait til the buds look 'done'...

Microscope or even a magnifying glass to make life easier.