Defoliating- Not sure if I can break it down so it makes sense, but I will try. I have no exact science to how I do it.
Let me state this is a routine that moves clones to flower at a rapid pace. One could easily be productive by grooming more in the veg state if you wish to invest the time... There will be variance from strain to strain and style of grow. I can only describe what I use for standard container growing.
First trim.. At about 3-4 weeks in flower I start to remove the oldest largest fan leaves if I feel there is enough to support more growth. I am sure to leave ample near bud sites and concentrate on interior and lower areas. Meaning I rarely take anything other than from the main stalk at this point. Main stalk can include multiples if we are talking a topped or LST'd plant. Proceeding lightly to minimize stress. I also cut the stem no where near the main stalk. I allow the leaf stem to dry and fall naturally. I feel I am inflicting the least damage this way. It can easily sacrifice the stem with no visible harm elsewhere. Not sure it matter but made sense to me so I do. Also by removing the damaged leaves I can much easier monitor any deficiency I may be having if one exists. Watching the the leaves turn necrotic and die can fool a newbie into over treating a scenario. Fresh litmus.. fresh test results...
Second trim.. is maybe another 3-4 weeks this time eliminating all fan leaves and diseased foliage. In this stage I trim lower growth that I feel is doing nothing but taking up nutes with little to offer down the line. Always keeping in mind the total amount of damage I am doing and stay within a reasonable limit. Would rather revisit the trim than to go overboard.