We are an Email Marketing start-up with multiple clients. We do email marketing on behalf of our clients. We generate leads, run email campaigns, and setup demos for the Client's Sales Teams. I have a question in this regard - 

How to setup different processes for different clients? 

      - Client specific Leads/Contacts have to be selected from the main leads/contacts data.

      - Client specific sales funnel has to be established

I found a related link - https://www.zoho.com/crm/customization/page-layouts.html

Can someone help me with this?