Here's my favorite opener. It's best for those big scary events with lots of people who I don't know.

"Hi, I don't think I've met you yet."

That's it. It shows: - You're in the habit of meeting people - You have met a lot of people, so it's easy to get them mixed up - An indirect compliment

Trust me, if I can use this effectively, so can you. The purpose of an opener is to start a conversation, and this does just that. Other than this, I'd have no idea how to start a conversation and I'd be that guy awkwardly standing around while everyone else is socializing.

Typical responses to this include: - Their face brightens up and they smile - They introduce themselves - They introduce their friends - You're now in the middle of the conversation