How to ask a girl out?

^ Except spending time with someone you like isn't "so much unnecessary effort". For one thing, if that's not enjoyable, it's all not worth it.

Well, wouldn't he be more disappointed if he had invested a large amount of time into the girl just to find out that the relationship wouldn't have worked, when he could have just asked her and find out in at most five minutes?

Then again that doesn't seem to be the context of this thread. I would recommend, if the thread starter is in high school or below, for him to just drop it. It's most likely a waste of time even if he succeeds; and if it really isn't (which is not unheard of), what I say is powerless anyway. Heh.

Even if it doesn't succeed, it'd be is an invaluable experience for him.