Make a long, lazy, slow-paced swing to create a high trajectory. This gets the ball up high so that it lands softly and does not roll. It is a risky shot, so only play it once you have practiced it sufficiently.
Most thin or topped shots are not caused by picking your head up, as commonly believed, but rather because your muscles tense up and shorten the distance from your club to the ground
You need to maintain your balance throughout your entire swing sequence, this requires the torso and arms moving together allowing you to maintain your center