How do I message a girl I like on facebook without sounding like a creep?

[Gary]

I asked a question about this girl I like and advice on how to ask her out, probably a good idea if you read that first, and I was told to talk to her on Facebook but I don't want to message her on Facebook out of the blue and sound like a stalker, I thought of asking her if we had any homework and then trying to change the subject so I could use that as an opener to our conversation? What do you guys think? If you have any more suggestions, that would be helpful