Short answer is to stay down through the shot making very ball first contact. Best drill for this is to hit some mid-range pitch shots with the ball teed up very slightly and another tee or tee fragment an inch or so in front of the ball. Practice clipping the ball, leaving the tee underneath it untouched and making contact with the tee in front of the ball. It’s a bit of an exaggeration, but very effective in grooving the feel.

Many things go into making it spin more. Your swing, your clubs and your ball. You may just need to update equipment to make it happen. I hit down on the ball pretty hard so I get a good amount of spin naturally. I sometimes take monster divots with my wedges if it's soft but it works getting the ball to stop. Haha

With longer approach shots have found that I can spin the ball back with the lower flighted shots so I put the ball back in my stance for these. The higher the shot the steeper the angle of descent and the green will depress and stop the ball from spinning. Obviously dry face, clean grooves, tight lies and ball first would be the best ingredients.

Look at the guys who make a living doing this. Those with the monster divots seem to be the ones that are pulling the string on there shots to the greens. Angle of attack and follow thru creates spin on the ball. Like those of us who shoot pool, you point down on the cue ball to bring it back. Greg Norman was one who could create so much spin he seemed to have little control of it at times. He was an attacker of the golf ball on all his shots. Do not think he ever hit a half shot. He might check out some of his videos regarding spin.