Why is it important?
In the beginning you may be told exactly what to do. After the newbie gains are over the process needs to have a larger influence on the lifters ability to make good training decisions and to larger extent good life decisions. These decisions will shape your training plan. You are the only one in your body and the only one to perceive your experiences. No matter how good an outside professional is your ability to do the self-work required for growth and improvement weighs on your shoulders.
Here are 3 ways to build lifter autonomy
1) Practice using the rated perceived exertion scale. When you are done with a set, rate it on a difficulty level of 1-10. This helps detach you from a number removing expectation allowing the difficulty level to guide you.
2) Be okay with changing the plan. If 135 feels really hard, bar speed is slow and your form is slipping, rest longer between sets, lighten the weight or change the rep scheme. This helps you be objective about making better training decisions. Do not to exploit this, be honest to yourself and don’t just change stuff because you don’t feel like trying hard .
3) Don’t do things that don’t work. If overhead press hurts your shoulder try changing grip position, load, and reps, and see if it helps. If it still doesn’t help do a different exercise that doesn’t cause pain. Beating a square peg into a round hole doesn’t work for long term success. Gather things that work and rotate through them.