If You really want to gain size stop reading articles out of magazines and find a trainer that knows what they are doing.
Eat organically, you are what you eat (if you give yourself a 59 cent hamburger you are giving your body 59 cent muscles that make you look like garbage.)
Eat According to your metabolic type, "the metabolic typing diet"
Lift mainly in the 8-12 rep range
Your temps should range from 3-1-3 to 4-1-4 and no more
You total time under tension for each lift should only last 60 sec or less (this is because you want to produce as much Testosterone and Growth Hormone.
Don't lift longer than 45 min per workout, less at a higher intensity equals more.
This would be different if you were on pro-hormones or juice, because of the recover time.
You shouldn't be performing any cardio
Lift according to your genetic makeup and your muscle fiber type if you tend to be more of an endurance athlete you will do better lifting little higher reps, if you are more of a speed athlete you will do better lifting a little lower reps heavier weight.
Supplements and other things can help in achieving mass as we all know what the pros use and most amateurs lifting in the gym.
Though follow science it can do way more for you than just taking some pill.
Mass is easy to gain when you lift correctly, don't waste years trying to reach your goal when you can invest in a trainer that can get you tons of results now.