Since you are into web design, try different types of online marketing (social media, forums, online directories, etc.). Try also to have a blog by telling to the people what you know about web design. In that sense, they might see you as a professional web design business.
But the most important thing here is that give your very best in every web design project/client you will have. If your projects are really with quality, Word of Mouth Marketing and Viral Marketing will just happen.
Good luck and all the best!