You may want to look at a push pin call (HS Strut makes a Gobbler Grenade) You can make soft, subtle sounds with very minimal movement. I think they even make some that you can mount on your shotgun so you don't have to move your arms or shoulders when a turkey is within view.

I've been working with my mouthcalls every day - I'm really struggling with them too. I just don't have the confidence I need to have with them. Some people will do NO calling, if the turkey is within view. They'll scratch at the leaves if possible.

Mouth calls are the best option when it comes to zero movement - but I am getting to like my Gobbler Grenade.

Kim