Learn a proceedure. Do the procedure to the letter. If it works, do it again. Do this enough times and with enough different proceedures, and you’ll have a working knowledge of what is effective and what is not.
Then, synthesize all your knowledge and do something new. But don’t pretend the proceedures you followed to figure this shit out were your invention. And don’t pretend that you’re the only one who could do it. Proceedures exist to pass knowledge to each other because anybody can do magick if they learn the right skills.
My counter to this would be from my own personal experience. Whenever I follow a procedure to the letter it seldom works for me. When I adapt a procedure to my own paradigm and personal experience, I have a much higher rate of success.
I would say that doing the exact procedure was beneficial, and I learned from doing it. But I am not sure if it is absolutely necessary.
This observation comes from someone who has a few years of experience. Not saying I’m some great magus, but Iv’e done some work. Others may have a different experience.
Overall, I think people are better off learning as much as possible about any given magical operation before trying any version of it.