The body fat levels that an individual comfortably fluctuates between I think are dependent on many factors, most of which have already been mentioned: diet, age, genetics, exercise level, consistency. For me my comfort range (the percentages within which I can manipulate my b/fat levels without much effort) is 10-13.5% according to the calipers. Below 10% I have managed but find the caloric defecit uncomfortable, and I usually struggle to eat enough to bulk beyond 13.5% - my metabolism and energy levels seem to ramp up like crazy and my appetite drops way off. Hopefully a sign of good leptin sensitivity.
Once getting to b/fat percentage lower than 10% though I'd image it's easier to hold it at that point than actually getting there.
I have never really followed a traditional bulking plan for any significant length of time and always 'lean bulked', but am now considering for the first time in my training life really doing some pure bodybuilding rather than mixed goals of fitness and physique development - hence this thread.
To summarise so far:
generally people prefer 3-4 big meals a day (plus shakes) rather than 5-8 small feeds or more
eat lots at night and first thing after waking
15-20 calories per lb
70/30 clean/junk... i can handle that (i also have a fast metabolism

)
Good oils with each meal and lower fiber to help appetite.
Also like Rabs post and approach - simple to understand = easy to stick to
