What do you mean by guild (theirs guilds for Magic?), anyhow the best advice I can give is do your best and don't over think it if you mess up or feel they saw something don't stop in your tracks , finish the trick, get to the finish line.
My best reaction I have ever gotten was when I was at a friends birthday party, there was about 12 or more people there sitting on different couches, so I decided to pull out my cards and do the "Three Queen Monte". I set up for the trick, had one of the gals there pick a card put it in "half of...