Hi! I think it also depends alot on your body type, and the condition you are in at present i believe, also the type of look you are aiming for, i use to keep around 12% BF all the time, now i have this diabetes i am at 8% BF, because of the low carbs i have to consume now to keep my blood sugars low.
But before i use to experiment alot with training and diet, mainly with different types of foods, I found i gained best, with good carbs and a good high protein diet, also never much more than about 3000 calories each day, i would recommend nearly double that for ectomorphic body types though.
This is for natural BB btw, i know before i got this diabetes i took my arms up to just short of 17 1/2 which is good for me as i was 12% BF at the time.
I think with the training part to aid the diet, it is best to work each body part well, whether with high reps or low reps, remember the joints, i was allways taught to train dont strain, look how a simple exercise like concentration curls can peak those biceps in time.