Never base your design on a single photograph (or illustration) provided by your client.
Insist your client provides a series of at least 10 photographs (or illustrations) which are actually going to be used in the website. There can be an enormous difference between the material a client provides during the kick-off meetings and the material which will actually be used on the website.
Of course I’m talking about websites with a CMS system, where your client can manage the content, including pictures, by himself. An online catalogue, e.g.