Bodybuilders typically go through different stages of development in their muscle growth.
When you first get started everything you do seems to work.
You get stronger and bigger everyday.
This mass building stuff seems easy.
Then something happens...
you hit a wall...
your growth slows...
your strength gains slow...
things are just not the same.
This happens at different stages for different people but it does happen.
As you exit the beginner stage it becomes obvious that your training needs to change.
Now that you have some experience, and some time under the bar you are entering the intermediate stage.
Congratulations, you are no longer a beginner.
Like I said the rules have changed a bit if you still want to build muscle.
You are about to discover the number one mass building tip for the intermediate lifter.
The number one tip I could give anyone at this stage would be to get yourself on a structured muscle building nutrition plan.
I know, not what you wanted to hear, you were looking for some high tech program or deep dark bodybuilder secret.
Well truth be told, simple works best.
When most beginners are starting to workout and heading to the gym, they're working out hard but still eating whatever they ate before.
Most lifters have little to no concept of nutrition for muscle building.
Of course they are just beginners, and we've all gone through that phase.
I started this way, and you started this way as well, unless you had a pro coach help you in the gym and design the perfect plan for you.
At this stage, you go to the gym, fumble around with the weights, and your diet is basically crap.
But once you've been training for a while, you realize it's the poor diet that's holding back your progress.
You realize you need to fuel the machine correctly.
A lot of guys find that doing the training in the gym is the easy part and they actually look forward to working out.
It's the diet part they don't enjoy and so that's where they let things slip up.
So I'd focus on the nutrition aspect of body building to maximize your results.
My best recommendation for a beginner who's looking to make as much progress as they can is to find an experienced coach and look into getting a customized nutrition plan, or at the least get a good book on body building nutrition and use it to structure your own plan.
Some basic nutrition suggestions to help you gain more muscle:

• eat real foods, three ingredients or less
• drink at least 2 L of water a day
• eat lean protein and a fruit or vegetable at every meal or every feeding
• avoid processed foods and sugars
• as soon as you complete a workout ingest some lean protein and some simple carbs
• keep a detailed food journal, and include everything you put in your mouth
• eat more vegetables

These are just some of the basic principles that you need to understand the pack on the most amount of muscle.