apple tree pruning to promote spurs
How do I prune the shoots on my apple tree to create future spurs? (pictures below) On some trees like the one below there's a lot of shoots on branches and I don't have a sense cutting them back (others like the Arkansas black I have is forming more spurs). I've read that if I cut them back to one or two shoots it will push it to form spurs, but that doesn't seem to be the case. I've been doing summer pruning to keep it in check, but I wonder if the tree just has more vigor than I planned; and did I misread the information on pruning? Any help is appreciated (including recommended books, or general comments).
As background I am attempting to grow an apple tree fence. Becuase my space is limited, I'm keeping it 2 demensional, I use posts and spreaders to keep the tree in form. As much as I've read, I'm still a novice and this is a bit of an experiment. The fence row is a variety of trees, this picture is 'enterprise' spur forming on M111 planted in 2006 as a 1 year whip. Ideally I like it to get around 12 to 15 ft.
Tree followed by a branch (see the 6" shoots, no spurs).