There is a big difference between a beginner, intermediate, and advanced bodybuilder, and it's not just size. See, what you have to understand is different levels of muscular control and their relationship to intensity.
A beginner does not have the same level of muscular control and contractions that an intermediate or advanced bodybuilder has. Therefore, his main priority should be lifting the weights. Getting the weight from point A to point B and getting bigger, that's the goal. As a beginning bodybuilder I only focused on moving the weights, not the actual contraction of the muscles. And I put on 36 lbs of mass in my first year, so guess what? It worked!
As you advance, the growing phases become more and more difficult, and eventually there comes a point when you need to focus on volumization and muscular contraction. This would mean possibly taking the same weights you used as a beginner or intermediate, and finding a way to make them feel heavier and more challenging. The way to do this is by focus and contracting the muscle harder. When you perform a bicep curl, think of squeezing your arm extra hard, not just enough to lift the weight, but enough to lift the weight and then some. Almost like you are performing a bicep pose with a weight in your hand. This my friends, is what gives volumization and hardness to a muscle!
If you've had a few years in the gym under your belt then you can start getting into this type of training. This is the kind of training that is pain; it's pumping and cramping of a muscle to where it has no choice but to volumize. The muscles will look fuller and rounder with this type of training, you go from being big to being shaped AND big. You are no longer this huge block of mass, but individual body parts stand out and become much more noticeable, even through a shirt!
Use less weight
A wise choice to make when it comes to this training (something I do all the time) is always grab about 10 lbs less than you think you can use (on big lifts like bench and squats maybe 20-30 lbs less). Now, your goal is to make this less weight feel heavier, and the only way to do that is through concentration and “adding weight in your mind”. Yes, I said adding weight in your mind. I can pick up a 10 lb dumbbell and make it feel like a 40 lb dumbbell simply by focusing on that weight harder and harder and what my muscle is doing.
Now, to the onlooker, they won't have a clue in hell what you're doing! To them, you're just this huge guy training with pussy weights, must just be steroids right? WRONG, they have no fucking clue. You are a master at your craft, a man who can get lost in his level of focus and intensity.
My friends, if someone told me that all I was allowed to use on bench press anymore was 135 lbs, guess what? I wouldn't shrink a fucking bit! I just know how to use my mind to accomplish what I need to in the gym. It's all in your mind! If you go watch these ridiculous videos with these pro bodybuilders, you will see all of them using loose form and sloppily tossing weights around.
Well here is the deal, they know they are on camera and they are no different than anyone else. They do not want the world to see this huge guy with 22″ arms curling 20 lb dumbbells, they wanna play the part. Therefore they throw around major weights for show. The vids are all for show! But I'm here to tell you that isn't the way that guy normally trains! Don't buy into that bullshit for a second. You're just not going to learn a lot from videos like that, they offer nothing.
So get the weight out of your mind for a minute, learn to take lighter weights and make them feel heavier. Then as you develop real strength you can go up in weight progressively. I'd suggest one day every few weeks per body part where you bang the shit out of heavy weight and just lift it. But 90% of the time focus and muscular contraction should be your priority, at least if you want to look anything remotely close to a bodybuilder!