a lot of that depends on the intended size of the plant etc etc.. your familiarity with your enviornment as far as how deep you get good weed into canopy..
outdoors, i would not trim much off. unlike indoor, the lower buds can easily be swimmign in 2000 umol/s of PAR. It's not teh same context as indoors where just 12-24" into canopy can be an extremely reduced umol/s intensity of PAR. (Photosynthetically active radiation = PAR - lol or close enough, it's off the top of my head)
So, for an outdoor plant, trainign and spreading it out is the best way to go.
when budsites form, if you see sparse amounts of pistils on some lower growth tips, you can change your mind at that time... but these will only be the heavily shielded areas of plant.
leaves power growth and buds... only remove what you must and have a good reason to do so. same with growth tips.. outside most will be useful.