Making yourself stand out from other grocery businesses around you. You can do this by advertising, or by having items in your store that nobody else has.
Set a price to charge for goods, find goods to sell and advertise, approach food companies and offer a deal to sell goods cheaply, Business hopefully will grow.
Competitive prices. Managers that buy quality fruits and vegetables to sell. In store meat packers. Friendly cashiers. Nice presentation of all foods. Helpfulness.
The number one factor for any retail organization is location. For a grocery store you will want to evaluate your competition and go to a place that will profit.