A good website design firm should be able to translate your discussions with a solid website design plan. After several discussions ask the webs design company for their design ideas templates and if they reflect the vision of your own website and take full determination of your goals.
Besides, ask for jobs they should be able to provide list of web pages to various industries. Also, ask them if they have done their job in the past. Another feature they should be able to clearly talk about, such as contact information, content, site structure and key content color schemes, themes, fonts, use the main elements to be effective.