If You really want to gain size stop reading articles out of magazines and find a trainer that knows what they are doing.
1- Eat organically, you are what you eat (if you give yourself a 59 cent hamburger you are giving your body 59 cent muscles that makes you look like garbage.)
3- Lift mainly in the 8-12 rep range
4- Your tempos should range from 3-1-3 to 4-1-4 and no more
5- 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.
6- Don't lift longer than 45 min per workout, less at a higher intensity equals more.
7- This would be different if you were on pro-hormones or juice, because of the recover time.
8- You shouldn't be performing any cardio.
9- 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 a little higher reps, if you are more of a speed athlete you will do better lifting a little lower reps heavier weight.
10- Supplements and other things can help in achieving mass, as we all know what the pros use and most amateurs lifting in the gym.
11- Though follow science it can do way more for you than just taking some pill.
12- 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. And if they don't get you results fire them immediately