You can top the plant and use that as a clone but why would you want to cut off the very things that create the bud? Leaves are there for a reason; they are the solar collectors that make the buds.
Light penetration to budsites which are unexposed to light due to the mass amount of foilage.
If you've never done this then your missing out on yield my friend because a plant takes up more than enough light energy even when you prune it.
Well, the word from Uncle Ben, who is a botanist and Master gardener, says that the leaves make the bud and if you put a bag over the bud it does not matter because it's the leaves that convert the light energy into carbohydrates and that creates the bud. Light getting to the flowers is insignificant. You hear a lot of wrong junk on this forum, as if growing MJ is somehow a whole different game than growing orchids or tomatoes.