Reverse incongruence is always fun! What you do is make a negative statement which is totally incongruent to your body language, it's something we are all good at doing but your reversing it!
A great one to say as an example is "Im not very good with women" meanwhile smirking and giving off alarm bells too her.
What I think this does is gives her a very strong perception of who you are based off HER decision on you and not what you say you are (ie the opposite). It puts her into a playful mood because she thinks your fibbing in a fun way and also telling her that your a bit of a ladies man, so everything you do or say to her is then looked at from that angle and that she must watch out for you getting into her pants, which is handy that she is therefore thinking about you getting into her pants
@Fatochre - I have done this before as well can confirm the same kinda response. Although I said roughly "Im not very good in bed but thats because I spend most of my time licking the bottom of pringles tins".