First off, it has to be seen, so you gotta be in the correct area, the decoy must be visible.
I use scent and grunt both. Ever calm and or deer dander is a good start. I also have used doe esterous with tarsal gland.
I have had better luck with movement, like a hanky ( white) tacked to the tail, to blow in the wind, or on a string to be moved by me. Doe bleats and tending grunts help to get other deer attention that may not see your decoy.
I ahve found doe will approach from the front of a doe decoy, eyes locked on the face of the decoy and buck usually approach the rear of the decoy, scent checking and grunting softly.
Slickhead is correct however, when it works it works great, and when it does not ... it don't - plain and simple.
Keep you scent off it and good luck to ya.
Bob.