Very rarely. Because 99% of my interactions are with family, colleagues and friends. It just is not in any way possible. But when I interact with strangers, when I find them attractive, I flatter/complement. It is always well received I guess that is flirting?
The woman from plumber's office called to say "sorry we do not service your area". I got mad. But I said "You broke my heart". The call ended nice. My wife was amused. I told my wife that is better than showing her I am mad Such things happen rare so I remember most of them...