Try to remember this...A gobbler usually approaches another gobbler/jake from behind, to bushwack him...With a hen, a gobbler will usually circle around to the front so he can impress her with his fan...A jake or gobbler is usually following a hen...

So, I usually set them to my left/front since I'm right handed with the hen in front and the jake about 4-5 steps behind her...

The final thing to remember is there are no hard fast rules in the turkey woods and many times the decoys are best left in the bag...