These are the most important bodybuilding tips you must be thinking about when you are at the gym.  They should always be on your mind and a primary focus when you are working out.  If you follow these free bodybuilding tips, two things will happen.  The first, and most important, is your chances of becoming injured will be greatly reduced.  The second is that your workouts will be much more effective.  So without further ado, here are the best bodybuilding tips to help you gain muscle.

1.  Keep your body in a comfortable natural state with correct posture, regardless of what exercise you are performing.  This means if you are standing, keep your feet at shoulder's length apart, pointing straight ahead.  If you are grabbing the barbell, keep your arms at shoulder's length.  For any back exercise, your body should retain good posture.  You should always feel comfortable and not at all awkward when performing each exercise; if you do, something is wrong with your positioning.

2.  Never break form.  This is one of the most important rules, and it is especially important when you start getting to your last repetitions, and they start to get really hard.  In these situation a lot of people will break their form and "cheat" in order to get more repetitions in.  DO NOT DO THIS!  Not only is this very ineffective in terms of building muscle, it is exactly why people get injured.  If you are straining to get a last repetition in, but can't complete it without cheating, just stop. 

3.  Breath out when exerting yourself and breath in when preparing for the next repetition.

4.  Do the exercises in a slow and controlled pace.  Never rush through (which I realize can sometimes be very tempting).  Doing it at a controlled pace is much more difficult, but also much more effective. 

5.  Shoot for between 8 and 12 repetitions for each set, doing three sets total.  As with all exercise, its good to vary things up.  Sometimes you will want to go for higher weight / lower repetitions and vise versa.  But the general consensus is 8 to 12 repetitions, three sets total; make sure that is the average you are hitting when you go to the gym.  

6. Another body building tip is to always warm up. It doesn't make much sense to start lifting weights when your muscles are cold - that could lead to injury. A warm up is good to get the blood flowing so it won't be a shock to your body when you actually start your heavy lifting. What should you do to warm up? Some light cardio for 10 minutes will do the trick perfectly. A light jog, some jumping jacks, shadow-boxing, etc.

* Note on Stretching: Should you stretch? There are mixed feelings about this one from all kinds of workout gurus, saying yes and no for all different kinds of reasons. My personal opinion: I don't stretch because I feel that my light warm ups do the trick and I'm ready to go after that. That being said, however, its up to you whether you want to stretch or not before your workout.

7. Always do the same number of repetitions for both sides of your body. Every person has a side of their body that is stronger than the other side. Make sure you always do the same workout for each side so you don't start to develop a lopsided body. An easy way to do this is to start with your weaker side, and then do the same number of repetitions with your stronger side.

Those are all my tips on bodybuilding. If you follow these rules, you will be 90% ahead of the game compared with all the body builders out there. Not only that, you will see results a lot faster and have a much better chance for staying injury free.