A few things that have helped my students are:
1. Place a tee a few inches in front of the golf ball and try to hit it instead of the ball .
2. Place a golf towel a few inches behind the golf ball and try to not hit it.
3. Go into a fairway bunker and draw a line in the sand; make several swings trying to hit in FRONT of (target side) the line.
4. When hitting balls on the range, always place the next ball you’re going to hit on the BACK of the divot you just made, never in front of it.