If you want to play the facebook game I guess, I'd not go for out of the blue messages, I'd rather find hot girls that comment on friends statuses so you can actually have a group conversation with your mate her and anyone else.

She then gets a bit of your personality and has had a bit of fun talking to you with everyone. You can have a bit of a flirt with her there on the status and only then message her privately after saying something like "At first I thought you were a bit strange but you seem cool..." then get her talking.

That way your just having fun again like you would in a club or anywhere else, if you message her out of the blue no matter what opener you use or if you just randomly add her then you're going to be coming across as trying to pick up on her and her defences will go up.

That would be a far better way if you REALLY want to play the Facebook game.