The only way to learn is by experience. What you do before you call is the most important thing you do and will determine your success. I am not a pro, but have killed a number of coyotes in Pa. Don't think you can go out there and call in and shoot high numbers of them. Never call an area where you can't set up right, even if you can hear them howling. The sound you use don't matter so much as the wind direction, your approach, if your concealed, etc...most distress sounds work great. My favorite is rabbit distress, and my favorite howls are female invitation and a long lonesome howl. Never overcall an area. Usually the coyotes will get very educated if you do, and never tell someone else your honey hole...trust me i learned the hard way...