Unless you're lucky enough to be able to train on wild birds, bird launchers are the only way to simulate a wild flush. I like the DT Systems model because they allow you to load birds in through a trap door in the side. This is much easier than the other models that essentially require three hands - one to hold the bird and two to close the trap. The quail size launcher is the correct size for quail, pigeons and chukar. http://www.gundogsupply.com/bl509.html You'll want to start with at least two launchers. There are some neat things you can do with the ability to simulate multiple birds flushing from the same location.
