When meeting people for the first time, be it possible clients or anyone else. I believe it is important to be you and not pretend to be something you are not. Eventually, if you try to be something you are not, it will come through and that can lead to awkward situations. But, if you always be yourself, then everyone knows what to expect and they can choose to either accept that or move on.
DISCLAIMER: This post is older than one year and maybe out of date.