I have loved reading through everyone's suggestions! I
"ditto" them all.
One quilt store I went to featured a special fabric or color every other month. Cutomers made 12" blocks using it and then brought them in where they were hung in the store. The next month customers voted on which one they liked the best (votes were $1.00 each to offset the cost of the backing and thread used for the quilt). The blocks were then put together by the store personnell and quilted by them. The winner got to chose which charity the quilt was donated to. It was amazing how popular this was!
Another store did an "art bra" contest and donated the proceeds to breast cancer research. I think activities like this promote civic awareness and are also lots of fun!
My LQS has an Idea Saturday every other month early on a Saturday morning. The owner presents 5 ideas which are also written up in a booklet free to the attendees. We love meeting an hour before the store opens officially for this and most stay to look and buy.
She also has a show-and-tell once a month, again on a Saturday morning, at which pople can bring in a quilt or other quilted project to show. People have brought in not only projects they have done but family/antique quilts so we have learned alot about quilting history. She limits it to 4 people at a time so that it does not go on too long.
My last suggestion is to put as many of your shelving units for your fabrics and other items on wheels as you can. You can get ones from the home improvement stores that have levers on them to act as brakes. When I was teaching early childhood, I had my husband put them on all my shelving units. It made rearranging my room, cleaning, and making special areas so much easier!
I am really looking forward to hearing more about your shop.