have a good product that people actually want. make it easy to buy either have a very unique type of stuff nobody has, or have a price stuff at a comparable price to neighborhood store. take care of inventory - make sure clients dont' have to worry about shipping. ADVERTISE make $$
The online store should be more trustworthy, No busy, Easy navigation, Try to show quality pictures, one page checkout, give more product pictures with good quality and product information. These points are may help you to convert more deal. May this help you.