I shoot mostly 35mm.
My subject-to-lens distance really depends on type of shots I'm taking. For portraits, I typically use 105mm. For half-length portraits typically ends up 3 to 5 meters, maybe? Closer (obviously) for tighter shots and farther for longer shots. If my intention is full-length only, then I'd probably use shorter focal length to keep things more practical - say 70mm'ish so I'm not megaphone away from my subjects.