Early on in my golf exploits, I swung the club like I was trying to kill a rattlesnake with a broom. It took a number of years of concerted effort to get away from that degree of unharnessed aggression.
Being self-taught (didn't take a formal lesson for several years after I started playing) it was challenging. Being barrel-chested and inflexible, 3/4 was a full-swing for me, as I've never been able to get the club to parallel in my backswing without my right arm completely breaking down (I'm a lefty). If my right arm broke down, there was no leverage whatsoever. So I just learned to live with a 3/4 swing, kinda like JB Holmes who seldom gets his hands beyond 10 o'clock at the top of his swing on the imaginary swing dial.
When I got my first lesson, it was the first thing the instructor pointed out. He pointed out the value of thinking more in terms of controllable aggression vs uncontrollably hard. Uncontrollably hard had no transition from backswing to downswing. Through further conversation he wasn't advocating a long pause at the top of my swing before engaging my lower body to initiate my downswing. He simply wanted me to slow my swing down naturally. To do that, he put a tee in the ground and said, "pretend this is your ball. Now, hover the club about 6-8 inches beyond the ball, and start your backswing from that 6-8 inches beyond the ball without grounding your club. What you should feel is a more natural takeaway that feels unhurried and more fluid. That should be more of your normal swing rhythm."
Sure enough, my swing felt much more rhythmic and unforced.
But how I perceive my swing aggression is different from everybody else. "Soft" doesn't translate for me, because to me - soft means trying to feather a tee shot with driver to a distance considerably shorter than what my usual full swing offers. On occasion in the past, when I would come to a long par3 (215-220yds) I felt comfortable with that "soft" translation. I felt like I could control the ball with the bigger face of a driver with a "soft" swing versus the normal aggressive swing with a fairway wood in that situation. I could control the face angle much easier obviously because I wasn't swinging nearly as fast.
Which brings up another good lesson I received from Gwog (from FGI of old). Gwog would occasionally talk about taking longer clubs and figuring out how to hit them to specific shorter distances to help him improve his ball-striking and tempo. "Some clubs," he would say, "we swing with much more speed than we do with others. The wedge, for example... If you swung your wedge as hard as you go at the ball with that driver, Lefty, you'd shank it all over the lot. But what might happen if you use the same amount of energy with that wedge swing with your driver?"
He was also an advocate of starting a warmup session on the range with hitting a dozen or so balls with the feet together, to help get the sensation and feedback of proper balance. Another good lesson.
Gwog is a helluva instructor. Unfortunately he took a terrible spill a few years back and ended up doing some serious damage to his shoulder. Last time I spoke with him, which was about a year ago, he was unsure if he'd ever be able to teach again. For the longest time he was recognized as one of the top short-game instructors in Long Island. His ability to communicate the working mechanics of the golf swing was truly a gift. He never talked in techno mumbo jumbo, preferring to keep it simple and relatable.