Doing all the above will make you a great plus one. But don't shy away from going the extra mile to make sure your date has a really kick ass time. This may include offering to drive if driving is necessary. Because you don't know anyone there, being the designated driver is the classy thing to do. Offer to take pictures of her and her friends. Sign the card you brought with your gift with a nice, not weird message, even if you don't know the happy couple. The details make all the difference. And if your date is happy, chances are you'll have a happy ending to the night…or maybe even your own happily ever after.