Pay attention to the details!
As you become a more advanced lifter, it becomes increasingly important to pay attention to the details!
For the first couple of years, almost anything seems to work when it comes to building muscle, strength and burning fat. But as you become a more advanced athlete, you have to be aware of the different variables that can negatively or positively impact your training and progress.
So pay attention to the details. Mobility, stretching, flexibility, diet, training variables, principle of specificity, strength, hypertrophy, endurance, weight loads, intensity, speed... Are all different variables you must take into account if you want to make your programming optimal for your goals.
A good programming focuses more on what WORKS, rather than what hurts. So don't let that "no pain, no gain" mentality determine your training. Work smarter, not harder!