Hope this article helps:
Code One Magazine: Aerial Refueling January 1993
I've been out of the air-to-air refueling biz for 12 years now. From what I remember, it was dicey if you only did it twice a year for practice. If you did it twice a day over the period of a two week excercise, it became easy. That being said, I wouldn't want to be in on a multiple refueling.