I give a lot of advice here, but I'm really fond of this tip.

We talk about smiling here, you know -- smile -- make eye contact and approach, but what if she doesn't even return the smile?
You can't approach right?

The logic being: if she recieves your smile, she'll recieve your approach and you've already opened her without saying a word.

We all hate being ignored and so I decided I'm going to make her smile.
I smile at her, she gives me a blank look and so I smile again, this time I draw the smile on my face in the same way you might try cheer a glum person up.

The implication being, "Hey, I'm happy and so should you."

Your second smile will be met with hers, so now make your smile genuinely happy she is smiling.
Which says, "I'm glad you're now happy because that makes me even happier."

Who said you ever needed to invent a lame situational opener just to talk to her.
I'm willing to bet, she'd now be more than happy to talk to a guy that can do just that.

Smile, be happy!

swweeeeeet simple and I can def see it working...at my old job I would always get complimented by this cute chic (who I later found out was a MESS of a girl lol) She would say things like "Omg I always see you smiling all the time and I don't know, it just makes me feeeeel goood"