There's a saying when it comes to relationships: "Talk like best friends, play like children, argue like husband and wife, protect each other like brother and sister."

I'm having trouble with the "playing" part and am totally stuck on this one point.

There's a girl who I'm becoming close to but I'm having trouble keeping things fresh when it comes to play flirting on a physical level.

She isn't ticklish (or maybe I just don't know how to tickle correctly) but regardless, it gets old poking and tickling her repeatedly all night and not having any other ideas about how to engage her in a playful way. Not to mention people become desensitized to tickling relatively quickly in most cases anyway.

Any other ideas here on how to engage her physically in a playful way to keep things from getting too boring? I should mention that she's pretty shy.