When she writes a long, thoughtful reply to your seemingly thoughtful ad, make sure that when you respond back to her you hone in on the one small sentence that metions sex and ask her to elaborate on that. Don't write or ask her about anything else that she said.
Repeatedly ask for more fotos of her without offerring any of yourself.
End every sentence in your emails, which are full of misspellings and/or typos, with one of these ;-)
Redeem yourself by asking her out dancing to a place that she has always wanted to go.
Start to mess it up again when you call her and become confused because the name that she tells you, the name she has signed every email with, is different from the screen name on the email, even though you have the same scenario and she manages to remember your name.
When she asks you how many women you are currently seeing/having playdates with, pull evasive moves and don't answer, even when there's no reason to think, based on your correspondence with her that she will be put off by the truth, whatever it may be.
After finally answering the above question with 'zero', call her during her work day, and ask for "Liz" . Then act surprised when she says it is nina, as if you've never heard this name before. Come up with some sorry-ass excuse about a new phone and your klutzy thumbs and how you were trying to reach your boss, whose name is, yes, Liz.
Any one of these things might not have rendered it totally FUBAR, but all of them together means nina is home tonight enjoying the latest Almodovar flick and thinking incredibly nasty thoughts about its star after happily stopping by for a sunny musical party in celebration of this.