I think the most important part of your question is the last part where you say 'OK to do', as in you're implying that approaching is currently not ok to do in your mind. I think this points to a broader problem that young guys have it in their minds that approaching girls is not okay and is frankly unwanted, which in my experience on this site is false more often than true, but who can really say for sure anyways.
I think society, in its ever-growing protective state, has done a piss poor job of fostering healthy relationships and has instead encouraged guys to stop approaching for fear of being branded a creep who gives unwanted attention.
At the end of the day, it all comes down to a state of mind. You gotta change the frame to be that all the girls want you to approach them instead of the frame that you currently have, which is its weird, uncomfortable, and not okay.
The challenging part is reading the situation and coming up with a conversation starter that will diffuse the initial awkwardness and open her up to you. Its different for each girl and each setting, and can be impossible if you're not particularly outgoing and quick on your feet.
What's weird about possibly not ever seeing her again? Wouldn't that make it easier, in case you get rejected? If she's not interested, you're not really losing much after sharing a whole five minutes of conversation with her.
I would just do it! I was literally just taking about this with a friend. I don't want to beep my own horn, but I feel very blessed with my looks (which by no means is everything... you have to have a good personality to back it up) but not many men will initiate conversation with me first. I am also a very outgoing girl so that adds to this whole element but I would definitely say the type of man I am attracted to is confident! So just go for it! Everyone hates rejection but in the long run it won't matter! Just be you and be confident!
You need to shift yourself from the 'taking' vibe into a 'giving' vibe. Likely you feel worried of rejection, coming off as a creep, seeking validation, and try to justify why you're approaching a girl.
Just be upfront, honest. Pay attention to your feelings. You need to let go of this need for a 'reason' to go out and approach women.
And most importantly, learn to have a fun, care-free, and passionate time!
i never do this. i just talk to people who i have been introduced with.
I also don't use the "social media" because I would feel freakin' weird explaining how I met the girlfriend.
But the very, very few times I've approached I've felt awkward as fuck, and it's probably due to the fact that girls think that us guys think they are desperate when they approach us guys... so it's always in the back of my mind "Holy hell, she'll now think I'm friggin' desperate because I approached her" - and that's the reason why I don't approach