It really has a lot to do with genetic and biochemical/physiological individuality.
Some people can just pack on muscle quite easily, some are 'hardgainers'.
I do find the concepts of ectomorph, mesomorph and endomorph useful.
Women can train in exactly the same way men do.
Small differences between natural and assisted, naturals may need more time to recover than someone on cycle.
I am not that keen on the terms of 'bulking/cutting'. In general you have to put on some fat to put on muscle, but far too many people think of it as being able to eat as much and whatever they want.
The whole bulking/cutting concept can really open the door to yo-yo dieting, which we all know is not the best practice.
I think that calculating calories for maintainance, see if you make gains, and then adding 10-20% a week until you do start putting on muscle, is a much better idea.
Getting too chubby from 'bulking' can really set up a difficult dieting situation.
There is evidence that staying at a fairly low bodyfat percentage (around 17% for women, 12% for men) results in better nutrient partitioning.
Nutrient partitioning means that the insulin response from eating will be more likely to store nutrients as glycogen in muscle, or put amino acids in muscle, rather than store nutrients as fat.