Does your shopping cart have features and tools that are rarely used? Are you getting calls from clients who request help with your shopping cart?
Create an easy to find and follow tutorial that users can consult when running into a problem. Give instructions on creating and modifying an account. Show how to create wish lists. Guide a client on viewing their shopping history, and of course, step by step instructions on shopping your site.
Clients will appreciate the guidance and come back to a site they are now comfortable using.