Best position to officiate screening action

[Kansas Ref]

Thanks so much for helping me to get a good perspective on the parameters involved in officiating this type of play. Sometimes I felt that I struggled to get a good look at this action (I may have missed an oncoming screen that was actually moving) , on the other-hand I don't want be moving around constantly as if I am working a boxing match, so these responses will be used to help get best the look in these situations.