I don't ever start with a new client by talking design or even what they like. Instead, I speak to them specifically about their goals they want to reach with the site, I ask a number of questions to gauge their current knowledge of the right/wrong things in regards to site development. I ask if they want me to comment on their goals or about how they see their site/application. I then try my best to get them engaged in the 'Best Practises' for a given topic. All the time I try to demonstrate my knowledge in each area... I still don't talk about design.
Next we move on to the content and I put a high emphasis on this. Generally the clients start asking 'Well what's it going to look like? Or, when are we going to talk about our ideas for design?'. At this point, I introduce the importance of content and demonstrate to them how modern search engines are rating sites and the difference between all the different platforms that will connect to their site. Most often the customer do get that the content needs to be the main focus with a directive for all information to add value to the users' experience. They are not always successful at getting the content the first time, but we work through it until we feel it meets the information objectives of the site. It is at this point that I convince them to invest in a copy writer skilled in Web writing/editing.
Once we have all the content, we block it up on the site and arrange it into a logical number of pages and rough sections.
Now we talk about the design. It is easier at this point to defend better choices in the design as they understand how much information is on the site. Most of them want layout that looks like 'Better Homes and Gardens' and so you can introduce the concept of white-space, the golden-rule variants, and eye tracking results. We also discuss how this information will transfer to mobiles. If it won't go well on the mobile, then we agree to a rule that it won't go into the site.
Generally the graphic designers are a little uncomfortable with this way, but most of them adapt really well to the imposed boundaries of the information and the devices we need to connect to the information on the site.
By this time, customers generally call me for advise on all sorts of Web and even non-Web related issues, so in a sense the process has reinforced the idea to them that I am an technical expert that they can trust. This trust provides leverage for decision making.
This may not be possible with all customers although I am also careful who I will do work for.