Route

You usually need someone you already know well. Knowledge comes through communication, and if you're communicating, you're already in some kind of relationship, including a friendly one. If she doesn't need you in that specific way, the relationship simply won't develop and will remain at a friendly level, meaning you already have her, just not in the way you'd like. So, in reality, there are almost no problems.

But if you don't know her, what's the point?