I found that if you like a lot of their pictures and message them saying something like "Sorry for all of the likes!" or something like that. I've noticed that they always start a convo with me and flirt with me. I just tested this out 4 times and it works every shot. Now this may be due to my dashing good looks and not the initial convo starter. So a warning, if you try this and the girl just thinks you're a creep, don't blame me!
it's the other way around for me. I can't kick them off me fast enough to avoid a flood of likes and messages.
heh i know a guy that does this daily and facks about two to three chicks a week from doing this... he also lies about everything on Face Book lol ... job ... what he drives...etc ...etc and they buy it lol...