You are in the rough with an obstacle blocking the green. So you need to hit the ball so that it flies high and short with a soft landing.
You are playing from wet sand, thirty to forty yards away from the hole from a sand bunker with a flat or low lip.
A skulled chip or pitch due to hitting the ball on the bottom of the club instead of the clubface. The clubface makes contact below the equator on the ball and causes a low line drive. Anxiety will cause you to want to look up too soon and cause poor contact with the ball.
You have a downhill lie in a sand bunker. The ball is on a slope in the sand and you stand with your leading foot down slope.
The ball is sitting in shallow water and you cannot afford adding on a stroke due to an unplayable lie.
Your ball is in or surrounded by pine needles, twigs, leaves, or dirt. Remember, you cannot move the ball without taking a penalty. If you remove anything from under the ball and it moves, you need to replace the ball and add a on a stroke before even taking the shot.
The tall grass is wrapped around your ball or is sitting in the rough.
You need to pick the ball up cleanly off of the surface of the hardpan.
Swinging too hard will cause a bad transition from the top of your swing and will lead to poor timing and inconsistency.
Standing up as you swing because your sense of balance tries to keep you from falling down the slope or swinging too flat and hitting the ground before you make contact with the ball.