I had the pleasure of attending Co-operatives UK's Audience with Mary Portas. I asked her for one piece of advice that she'd give to a community learning to become retailers by owning their own village shop. In true retailer style, she gave me three for the price of one.
Create a totally personal service for your customers. We all want to shop with people who connect with us. So be someone who knows their customers.
Be someone who knows what they are selling. There are too many faceless retailers.
Too often the small try to copy the big. Be something that reflects who you are.