Web designers must stay knowledgeable of all the current trends in the Internet industry. They must figure out what services are expected, what graphics are most likely to be received well and enjoyed, and how a page will rank high in search engines. By working with clients they get a sense of what basic functions the web page or pages must serve, but they may also help clients formulate plans on how to keep web pages most approachable, and graphically interesting. In the end, as a web designer you must please the client. Design based on your clients needs and likes not your owns.
There’s a lot of debate about the qualifications needed to become a web designer. Some people are not college educated but have been designing and programming pages for so long it doesn’t matter. Degrees tend to be less important than demonstrated ability when choosing a web designer. Instead of viewing credentials, evaluate the pages a person has constructed to see if the aesthetic value is close to what you want. Experience is always better than degrees in the web industry.