I feel like some people will know who I am because I have a distinctive type of writing (some have called my writing that of a sheltered Mormon) but alas I don't care that much to change it just for an anonymous question and plus I am not that known.
Most Helpful Guy
The structure of your writing i find to be fascinating for an unknown reason. And to answer your question: Flirting consists of a person, being intimate, or really friendly towards another. Also, awkward smiling, play fight, passive insults (if that makes sense), and feeling very comfortable being silly with each other.
Most Helpful Girl
Honestly, for me, it's something that I could only ever feel out, it's hard to make suggestions because not everything will work for everyone. If I really had to give a concrete answer however:
Banter: Playful teasing and debating, keep it light hearted and fun.
Eye contact: Self explanatory.
Body language: Face them, keep yourself open (avoid folding arms or looking down).
Break the touch barrier: Light touch of the wrist or arm when they say something funny, light little gestures like playful bumping. My only "flirting trick" is that if I have the opportunity to sit next to them, I will let my legs point towards them and eventually let our legs touch. Lol *Dork alert!*