[ModusOperandi]

I think that if you have to be direct or if its someone you just set your eyes on for the first time then once is enough.

However, if you have time to kill and you personally believe that your relationship with said lady will escalate, then you have to be tactful. Throw a party or some kind of a social gathering. Invite her to the party, hang around her a bit more than the rest of the crowd. Wait a short while and throw something less vibrant...perhaps three to four friends (including her) to your place for dinner....this will develop some kind of trust and you'll also have a great idea of who she is and if she is really what you're looking for. However, don't let it delve into friendship. (be informal...just not too much) Before you know it...After doing all this, you will probably have an 80-90% chance of receiving a positive reply when you ask her out.

This method is not always full proof but it comes with a lot of perks...the main being that it offers both people the advantage of developing a little bit of trust and understanding.