how to become a web designer

Question

Sir I have completed DCS Plus Diploma from Aptech Institute 2011. I am student with skill of html5,Css3, java script, Sql Server, Php . how to design website with good graphics for customer. i know to how to code for dbms but how to design website graphics, logo, banner, Attractive form. i want to make career in web design. please tell me a complete details for my best career.