In regards to comment #6, it's always been a common sense rule to not mix your pussy with your pay check. Just avoid that completely, even simple flirting with a fellow employee. And yes, people do get fired for sexual harassment.
Start a conversation with a compliment, as suggested in comment #3. As you converse, her body language will tell you if she enjoys your flirting or not. If her body language is positive, she may even flirt back. If it's negative, end the conversation and leave her alone.
Heck, I flirt with almost any good looking waitress, check out clerk, etc. Even written flirting with some of the Companions. It makes them feel good that someone finds them attractive. There's a reason women spend billions of dollars on make-up, hair and clothing. It also makes me feel good when that attraction is directed back to me.
It's not Rocket Science.