Here is a thought,If you are using a hen decoy,Have it facing you,But not right infront of you. Set it up either to your left or right wich ever would be best advantage to you that way the Tom Thinks the hen doesn't see himand will come in.
By setting it of to your left or right He will be looking at Her instead of you. .................................................. ............o <-- decoy



.................................................. ............................X <--- you

Hope it helps,Ive tried to make a diagram but it just isn't staying the way I type it.