Re-read the creative brief and do your research on their company.
Do this before you meet with them or give them a call. Doing your research helps a lot before meeting/talking with the customer. You'll feel more confident talking to them. And they'll feel confident talking to you too.
Listen to their ideas about what they want for the website.
Ask them to recap what they wrote in the creative brief. Pay attention to the key words they say. And also make sketches and notes to help you remember.
Ask them for examples of websites they like, or how they want their site to look like.
You can learn a lot more about what they like if you ask them to show you what they want, instead of simply telling you.
Give suggestions on how to make their website great.
You could suggest things you've seen in other websites from similar companies that might help their business or attract customers.
If you're not quite on board about an idea, still be supportive on their choices, but also suggest a different, creative view-point by saying, "Yes! That's a great idea! but would you consider if we…?"
Ultimately, it's the customer's decision on what they choose.
Reiterate by saying their words back to them.
Do this at the end of the meeting/conversation. Make sure you and your customer are on the same page. Pay attention to their tone of voice, and what words are repeated the most because that's what's the most important to them.