If they are coming to within 30 yards, you may not be getting busted on smell. Deer can be very curious, but with that curiosity is cautiousness. They will know when a ground blind has been placed in their normal area. Initially they will be very curious with it, and may come straight in to inspect it. ANY movement on your part will be enough for them to get spooked....as you have found out.

Try leaving the blind in place for a few days. The deer will become used to it' s presence, and will not be so cautious around it.

Another piece of advise that I was given was if you get picked off when you are trying to draw, just go ahead and draw back. You are busted anyway and the deer' s reaction may be the same watchng you raise your bow, as raising your bow and drawing back. Once anchored you are done moving and you can wait for the animal to give you a shot.