Tread lightly when upping your weekly mileage number, as fatigue and injuries can set in.
Learn how subtle year-to-year increases in volume can pay off in the long run.
How you're built, how you run, and how well you recover all affect your training load.
Learn how to apply motivation to set goals and make the most of your training time.
You will ultimately find the kind and amount of training you wish to undertake, or it will find you.
The answer, of course, depends on the individual.