Check out my downswing here. I call this the delivery position. The closer you get to impact, the less you can do—or undo—before you hit the ball. You're basically on cruise control. That said, you can monitor this position when you practice. Swing down, stop here, and check three things.
You can see my knees are shifting toward the target, and I'm starting to roll onto my right instep. This means I'm making a proper weight shift to my left side, which will help me strike the ball, then the ground for crisp contact. Also, I'm posting up on my left leg, pushing off the ground. That upward thrust is a major speed generator.
At this point in the downswing, a lot of amateurs have straightened the trail arm; they try to use it to create power from the top of the swing. When it stays bent, it keeps the club on an inside path to the ball, which is best for power. The trail arm shouldn't fully straighten until the club is a couple feet past impact.
With the butt end of the club back in front of my right thigh, the shaft is parallel to the ground, which proves I've kept my wrists hinged. Players who think they need to flip the face closed or help the ball up unhinge the wrists too soon. Keeping them loaded gives you a burst of speed at impact and prevents hitting the ground before the ball.