“A gentleman need never ask the time; a gentleman need never ask for a match.”
I have the contrarian bug today:
1) Be polite and smile your brains out, but let the bartender flirt first. Always provide a number, never ask for one.
A gender-specific injunction. If the bartender is a heterosexual male and you are a heterosexual female, flirt away. He is not allowed to complain, and any move to do so will be seen as braggadocio.