2d will work fine
there are alot of commercial 2d turkey decoys on the market
colr pattern,bird positions like feeding hen or alert hen ,alert jake etc
put the decoy where you would like to kill the bird at
if you can make them move some,that makes them even better
attach real feathers will help too
if you know where they are roosting, and where they are going to fly down too and which way they head from there
set up so that you can ambush them on their morning feeding walk after fly down
then you may not even need a decoy or call
if they are getting call shy,then i would use real soft subtle calling and very little of it
dont over do it.
if its early in your breeding season then a jake in half strut real close to the back side of a submissive hen as great set up
just remember, toms will usually walk up to a jake face to face(to fight)
tom will usually walk up to a hen from behind(to breed)
set decoys so that when he does come in that you get them in position to get the best kill shot
if hunting them with bow i find a back shot to be the best(spine them or upp the back door and gut them)
with a gun you realy would like them to stretch that nice long neck out for you(decoy positioning not quite as important for gun hunting)
good luck