how do you know your shoulders are in the correct position?

McDave suggested to me: have someone set a yardstick across the back of your shoulders at full draw/release ready.
Sure makes sense to me.

They should be below your neck and above your nipples.    

For me, my shoulders are in line with the target.

   

I have a "closed" and upright stance.  Your preferences may vary

where are they before full draw?

I think it all depends on you and how well you shoot that particular bow.
In general I think it best to have you shoulders inline with the draw arm / bow arm and all inline with the target.like the letter t.
You can line your hips up too but not necessary. ie: GFred and his open stance.

what does g fred do differently? so before i begin my draw my shoulders should not be at a 45 degree
angle? im open kind of directly looking at the target some?

G Fred totes a more open stance. Hips are 45* to target, give or take, but shoulders/ upper body  still turned to align with target.
Your shoulders can be anywhere you want when drawing, especially if just target shooting. Then lined up when you're at full draw.
When I practice hunting situations I try to be lined up before drawing to reduce unnecessary movements.
Don't over think this , play around and you'll find what works for you.

im having a hard time because my upper body and shoulders are 45 degrees to target maybe for me its not natural to rotate

seems like when i set up square to the target with my hips not open theres a huge difference, maybe before i was not getting back tension with hips open?

Being square to the target ( shoulders at 90* to target) will give you the most draw length. Probably the most consistency too.
Search on here for Terrys clock method . That should help

???

Facing the target?

Wouldn't that give you the least draw length?

i was 45 degrees open to the target with my shoulders and hips and torso i squared everything up and now can feel the back tension

Who said facing the target ??
Square meaning square angles. Shoulders at perfect 90* to target
Nhbuck1, glad you're figuring it out.

I square up to the target. I get proper alignment,  proper back tension and a lot less shoulder fatigue.

             
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