I am unsure of the best practices for creating contacts for an organization as I couldn't see a way to create information about an organization, only contact information for people within an organization.

Say I do work for 'ACME Products' and want to send an invoice to their accounts department person John Smith. Do I just create a contact 'John Smith' who belongs to ACME Products? When I go to create an invoice it asks me to choose from a list of contact names, So  how would I distinguish John Smith at ACME from another John Smith at another company? 

Thanks in advance!