How To Design Cs-Cart Template From The Begining ?

Hello Cs-cart Adminstrators, Users

I have searched for many posts to how to design a template cs-cart from the beginning, but I did not find what I want final

I want explanations of how to design work through Photoshop, and also through css, I find difficulty in dealing with the design, this could be the beginning of it

NB I can deal with templates from within the control panel, but I want to learn how I design from the beginning

Thank you