Ask a co-worker for her number...she gave it so easily so I though she was into me...texted her last week asking what she doing for the weekend...she said dinner with friends. She then asked what was I doing...I replied word for word : "Gonna be nice weather tomorrow was gonna take you out?"
Never got a reply...been 4 days
Gonna show up to work this weekend and see her....just gonna say hey then walk away 

This will make her brain melt completely.
She''ll be texting you before you know it. Standard 3 days of wait before answering back>you win.
Probably even better would be to approach her to talk about some work related topic were you are super relaxed. She will be asking herself the whole time ''why the fuck doesnt he ask why we didnt go out, does he not like me? Does he think im boring? Am i wearing the wrong bra BRRRRRRRRRRRRRRRRRRRRRRR
RRRR''