A pre-shot routine will help you block out all the distractions on the golf course and take out the negative thoughts you might have because it puts you in a consistent starting routine and eliminates last second swing thoughts
The angle your clubs lie on the ground will have a tremendous effect on your swing if it is incorrect, a one degree upright club will push your ball eight feet to the right on your sand wedge, which in turn will cause you to manipulate the clubface in order to correct that flaw
Chipping from off the green is probably an easier shot than pitching but you must play to your strengths and at least practice both shots for when one is not an option