Most Helpful Girl
Take a chance. Just honestly take a chance. You'll never know if you don't try. Be straightforward with this girl. Girls like when guys are direct, just not TOO direct.1
Most Helpful Guy
I mean, not making a big deal out of it is best. Just very, calmly and confidently at a relaxed but not inconvenient time if she wants to go on a date.
You can do this different ways, depending on her nature, or yours:
You can choose to use the word "date" or not.
1. Would you like to go on a date sometime?
2a. Would you like to hang out sometime?
2b. Would you like to grab a coffee/lunch after work/shift.
"Date" is more formal, and traditional and adult-like, and "hang out" is less formal and is used if your under 18, generally because of its informality. Getting a coffee is inbetween: more relaxed, less formal but is adult-like.
If she says no, just say something like "okay, no problem, I was just wondering" and move on to the next girl
Or you could use an emotive/imperative voice, and say "hey, let's [go on a date, grab a coffee, hang out]
To avoid a painful rejection if you really do like her, just before you ask her out, become detached from the outcome. You have to pretend that getting a girl means nothing to you. And if she says no act like it doesn't even matter to you and even just move right along and ask another girl out the next day.
To avoid a painful rejection, you have to act like womem are meaningless to you and her not going out with you didn't mean a thing to you. Be relaxed like you don't give a fuck. Almost like they are currency and don't mean a thing to you because you already have so many.
A woman is an addition to an already good life, not something that will make your life good.
If you handle it well and play it off like a pimp, this may at a later date get her interested in you, because she is bemused at how you handled it.
Have some ideas in mind for a date beforehand though.