I have recently read the book that the Wildlife Research Team came out with and found some helpful hints. Make sure you have it set up right with the wind direction. Also, i noticed a grunter will really entice them to get within close range. Never put the estrus on yourself though, otherwise the deer will be constantly looking in your direction, put it in a thick (pine trees) area where a buck will not be able to see into, making him have to come in closer if he wants a good time.
If you need anymore help let me know.