Friendly is #1, acknowledge that the customer is in the store. Also asking if they need help, some people love help, others hate it, so dont' hover. rewards program is a great idea, with you keeping the info at the store. I love saturday morning demo's on new products or patterns, rulers.
A big variety of fabrics, one of our stores is 90% thimbleberries, i like them, but not that much. Mini classes are fun, make and take, especially for small christmas gifts, knowledgeable teachers. One of our local stores sells her scraps in small bags, love them.