What is the rules regarding a low flying bird? Let it go and pick it up on the next drive? Does the shooting line keep moving to a different position after the drive or are you stationary?
There is a convention that one lets low flying birds go by. The choice of what constitutes low flying is up to each gun. Generally, when there is a flush of birds, ones eye tends to get drawn to the highest bird in range and, once locked on, go for that bird. Hit it and you can then take the next bird your eye is drawn to with the second barrel, provide it too meets your criteria for range and height and, of course, safety.
Each drive tends to take place at a different part of the estate, so the guns walk or ride to the next drive. There are shoots where the topography allows for one drive facing one way, then doing an about turn and facing the other. However, that does not, in my opinion, give the birds a chance to rest and settle down if they are flushed so frequently. Clearly there are big number days where there are more than enough birds to do this, but those sort of shoots hold little attraction to me.
Tim