Here are some common drills that you can practice at home without your mind focusing on hitting a ball.
Split Handed Drill: Split your hands apart then swing the arms, hands and club to get the feeling of the proper release of the right wrist (for right-handed players) rolling over the left wrist through impact. Do this enough times and you’ll incorporate this feel when you need it, during your swing on the course.
Mirror, Mirror On The Wall Drill: I can’t over-emphasize this enough. Look in a mirror at your set-up, down the line, face on and during your swing. You will see the difference of what you think your doing and what your actually doing.
Rehearsing Impact Drill: Take a mid-iron and find something solid like the corner of a wall and take your set up and press your club head against the wall, making sure your club face is square to the direction of the pressure. Be aware of your flat left wrist, left arm against your chest, hips open in respect to your target line and shoulders slightly rotated in the same direction.
Weighted Club Drill: Swing a weighted club for flexibility and improve your strength. Get an old club and fill the shaft with sand. Or go to your nearest golf retail store and buy a golfer's donut. Swing slowly at first and build up the number of repetitions. The added weight will make you conscious of the positions that are key in your swing.