I (22F) kinda do both the deep breaths and prolonging, my hardest to overcome is numbers…I work retail and when I have a total of $54.63 for example I drag on the ‘f’ in 54 and then start stuttering horribly on the ‘si’ in 63…very frustrating but I overcome it unless I have to repeat it then I resort to writing it down or have a coworker tell the customer the total. It’s embarrassing.