I pick a horizontal line where i prune anything below that on plant, because it is destined for trash buds and want more focus up top.
i err on the side of leaving some, as it improves hash yield immensely. bend it down and out of way so it doesn't restrict airflow in canopy. fluffy trichome coated buds are great for hash.
Axillary growth i'll lopp off if i don't think it has time to grow out enough to form anything but a piece of popcorn.
If i end up with an overpopulated area and feel it's too late to cut it, or it is too large to lop off without stressing plant, I bend it down and under entire canopy to create ore airflow, and just some more buds destined from hash bin.
in many cases this can reduce overall yield, but only if you count buds that you would never smoke. It will prevent such growth from using resources, and if you provide the same resources and light, otherwise, then it will spend it more on the better buds. all good.
Leaves in canopy -- some penetration is good. Don't remove all leaves from any one node and you'll probably do okay. light hitting leaves is the goal and limiting stretch on any terminal buds growing vertically that you care about.
