I think those who wait on the customers need to be friendly and helpful, but not overbearing. There's a convenience store I often go to buy soda. I always go to the same one, even if it's out of my way. The couple that owns it just make it such a nice experience, that I love just going to see them. They know how to make the right amount of small talk, and just make my day more pleasant.
Also, do quilting stores ever honor competitors' coupons? I've seen donuts shops do that, I don't know if that's possible for quilting shops.
Good luck on starting your quilting shop!