How to properly flirt?

There is no real strattegy when flirting. It's all vibes based and based on the person you try. Some might love a joke you make while others might thing it's offensive.

The only pointers I can give are: be chill, funny and nice to be around with. Learn how read the room and how zo banter. Also if you are strughling to talk to people you find attractive: ask genuine open queshions. People love talking about themselves to people that are interested in them.