Obviously I'm not a parent, but I thought I'd share a trick that my parents used while we were growing up. I think this was a pretty smart way to make our doctor's appointments go more smoothly: We were rewarded if we didn't cry before getting a shot.
I think this trick is smart for 2 reasons. First, it kept us calm while at the doctor's office. That was good for my parents, I'm sure, but it also kept our fretting down, which made us less anxious about going to the doctor in the first place. Secondly, although we were told not to cry before getting a shot, my mom was always sure to tell us that it was ok to cry afterwards, if it hurt. Knowing we would get sympathy, if needed, eased our fears. And more often than not (as I remember it), tears didn't end up being necessary.
And what were we rewarded with? Ice cream! (From an ice cream shop, not the grocery store.)
(Wedding cake with sprinkles & waffle cone bits and cookies & cream with Oreo pieces.)