Well just don't think about the pain. To be honest, I think about funny stuff when I'm getting a shot. Or just don't look at the shot when it's happening. Don't worry, it only lasts for a few seconds. :)
I don't enjoy shots either but as a nurse I find it easier to not look away. I think being caught off guard is way worse than taking control and watching the process. If rather see it coming and just breathe.