Pick up Carlson Championship Call's "Pro Duck Calling" DVD and study it like there's no tomorrow... then when tomorrow comes, study it like there is no day after that... get what I'm saying.
That is by far and away the best learning media ever created for duck callers. Nothing better. Practice, study, practice, practice...
Not just any call will work with the Carlson System... I highly suggest if you go that route to pick up a molded Carlson Equilizer duck call to go with it... affordable and awesome. I think its only $45 as a package? I wish I would have started on it.