Don't watch the boom. Pay attention to the director lights on the belly of the KC-135. The left row is for up and down and the right row is for forward and aft. You need to stabilize your plane directly behind the tanker and trim it so your jet will follow the tanker "hands off". Use very small adjustments to the stick and throttle. Make sure your approach is only about one to two knots faster than the tankers speed... and remember, small control movements. The boomer will do the rest.