Learning the art of flirting

 Start by realizing that every person is a flirtatious being and flirting is something we (even animals) do innately whenever we are interested in another person.This said, half the "problem" is solved. Then begin to work on learning how to convey your feelings in the manner you wish - boldly, funny, goofy, or a combo of everything.
Flirting should be something with your insignia - your swag. It shouldn't rid you of sleep, peace of mind etc, then it's no longer flirting - flirting should be fun, sexy and rewarding for you.

 Remember flirting is about two human beings expressing their interest in one another, allow for chemistry - physical or whatsoever.

There is no way for the other person to pick up your interest if you are not expressing it. Flirting is not in your mind, it's external. Show your interest by using body language. Smile, wink or make gestures. Don't force it. This is not a quiz and no one's judging. I personally prefer physical connection but be mindful of people's spaces and principles. Not everyone appreciates your hand, breath, tongue on them the first time. Some prefer just verbal flirting. Respect people's principles but never sacrifice your style. Flirt in your own way, afterall you're trying to win the person over for you.