In order to lift heavy weights, you must take advantage of leverage through joint articulation. For example, it's easier to lift a weight that is kept close to your body. The greater the weight you use, the better your technique must be. It's simple to see that when beginner's setup for Bench Press that they aren't in a well enough position to support hundreds of pounds.
The days have come where regular people have access to cameras, and thus recording your workout can fill you in on clues in order to improve your technique and leverage. Mirrors can be used to an extent, but it's easy to be deceived by watching only from a single view of errors that could be seen from the profile or rear view. Even if you are lifting lighter weights, you should maintain the greatest form you're capable of. This can be difficult because weight will alter your technique. The human body's center of gravity is at the hips. As you lift heavier weights, the center of gravity shifts closer to the weight you're holding. Therefore, it's hard to practice a Deadlift technique of lifting 405lb whilst only lifting 135lb.
Technique can improve through repetition, and so the more often a lift is scheduled, the faster your technique will improve. Create the correct, most efficient bar path, which leads to the least amount of work being done, because you will be using heavier weights to load the muscles and nervous system.
