Time to Think

Taking time to think of an answer to a question you were just asked is laudable, but it pales in comparison to thinking of an answer before a question is asked. The goal is to have a ready answer. You achieve this by:

1. Knowing what your message is, and--

2. Thinking through which questions you may be asked and how the answers to them could lead to the points you want to want to make.

You should approach every interview or Q&A as an opportunity to propagate your message, and not as an unfortunate chore you've been assigned. You're not there to answer questions--you are there to communicate your content and change minds.