Well i pretty much did all the things that n00b13 mentioned.. of course with the addition of knowing where you stand in her mind. That being said, I applied the very basic rule of going out on a date, is to let her know that you are interested and you like her.

I think it is imperative that you let her know that you are interested and would like to date her. If she declines to go on a date with you, you know that you shouldn't wait anymore and move on to another girl who is willing to go on a date with you. By doing so, you know where you stand and you won't have that feeling of not knowing whether she shares the same sentiment. And also reduce your own agony of waiting to confess to her and worry that how she would react.

Before you ask the girl out on a date, let her know the very reason you are asking her out - is that you like her and you are really interested. Most girls would react differently if you tell her that you like her, but here are the 2 most common reactions in their mind.
a) "Crap, what have I got myself into?? Now he wants me to be his gf? Dream on!"
b) "oh my god, he likes me too! Yey!"
If the reaction is the latter, congratulations you just got yourself a date. And to most girls, they'd appreciate the honesty, instead of hovering around trying to guess each other's feeling. If her reaction is on the other end of the spectrum, move on ! She is not that interested.

Telling the girl you're interested in does not mean that you want to start a relationship right now and right then. It is a very nice sentiment that you share with the girl that you would like to take her out and sweep her off her feet. You only start a relationship with someone after you've had couple of dates together. Going out on dates to know each other better, communicate and find out what each other like, and being comfortable with each other. Then only you decide if you really want to have that relationship that you've been longing to have.

Just my $0.02.