As you get more experience in a craft the more adept you should become in it. Those initial years are especially rough because you try to incorporate everything you've learned. It's understandable though - do as much as possible or include everything and it should yield the best result. However that isn't true.
A few weeks ago I was watching an episode of Top Chef. The chefs had to create a dish that "fulfills and even exceeds your mentor’s expectations of you as a great chef.” Paul Qui decided he would serve a chilled soup. As he finished plating he said,
He won the challenge. One of the judges told him,
"I keep on second-guessing myself. I really want to put more stuff on it. Being able to recognize that your dish is where it should be takes a lot of experience. And it takes a lot of discipline."
While his mentor said,"Young chefs don’t understand restraint. They want to add more. You knew that enough was enough."
These words are incredibly true for many areas outside of culinary arts. The discipline and ability to recognize when enough is enough rather than doing more displays an individual's maturity and experience.
"This is everything that I’ve preached to Paul over the years, is balance, of flavor, and not overdoing it."
In the realm of exercise, the new trainee's mentality is to include more volume, intensity, and exercises. They attempt to do it all because they think more is better.
It's not. Athletes themselves stick to a handful of relevant sport movements to prepare for competition. Olympic weightlifters are a perfect example: snatch, clean & jerk, and some partials of the full lifts.
Aim to strike the right balance for yourself. It takes time and patience, but reach the point where you're attuned to your training. The little quantified variables aren't hard-and-fast where they aren't up for change. Don't be caught up in the exact number of reps, sets, and rest periods. They're guidelines. Instead it's important to be flexible and adapt to your sessions based on how you feel.
Be able to know when enough is enough in your training and heed Bruce Lee's sage advice - "Be water, my friend."