kindness.
most people are a little nervous at events or meetings but if you ask each person you meet open-ended questions about themselves and their business, they will be put at ease. and oddly, the more people get to talk about themselves, the more they will remember you. an open-ended question is one that must be answered with a sentence instead of a yes or no answer.
as you meet people and ask those questions, truly listen for their answers. repeat back to them their name and the things they say in your own words, then ask them good follow-up questions. this will make you seem like the most interesting person at 