When an older guy (read around 65) whispers in my ears: 'Hola guapaaa!' I KNOW I am flirted with!
In Spain flirting is a totally different ball game I can tell you. I wrote a Hub about it and it's kind of shocking to the American standards I guess.
How I flirt? Subtile looks, a timid smile and later on a compliment about his trendy look and being in shape.
When do I flirt? To be honest....always. I got eyes for it and I have a mouth to make someone feel good about himself.
Flirting is just flirting and it makes me feel good too. The rest is not important anymore since I'm engaged and ready for the next step.