I am testing this pattern:
-Direct opener
-Assumption about her nationality (it is wrong most of the time)
-Assumptions about her (Do not use questions in the beginning to not make it sound like an interview)
-Conversation

For example:

Direct opener
Me: "Wait! You know... you are very attractive"
She: "Oh, thanks!"

If here she says: "but I have a boyfriend", be unreactive, ignore it and go on.

Assumption about her nationality
Me: "But you do not look from here... you must be russian?"
She: "No!"
Me: "You know... your eyes and your chin shape look russian. I know this because I had a russian girlfriend in the past. Especially your eyes are like the ones of the girls from Kazakistan (be very specific!). Has someone ever told you this?"
She: "No, I am actually from [Random city].

Assumption about her
Me:"You look like a creative kind of girl. You have that dreamy look. You must be some kind of artist like a painter or a writer".
Or
Me:"You seem like a rational kind of girl. You look like psychologist (maybe because she wear glasses). You seem like the type of girl that likes to study criminal minds".
She: No I am (or maybe you got it almost right and it is even better because it seems like you can read people) blabla.

Conversation
Now you can start the conversation, but you got some information about her.

For the conversation I try to remember and apply 3 concepts:
-Nouning
-Elicit emotions
-Flirting

Nouning is when you take out the nouns (the potential topics of the conversation) of her sentences and you choose what topic you would like to expand. You should probably lead the conversation towards something that could show your value (DHV). Nouning is not something that I invented you can google it.

For elicit emotions I mean to choose your questions cleverly to try to elicit some emotions in her mind and not to make the conversation too dry. For example, let's say that she studies medicine.
She: "I study medicine"
Me: "Mmm you must like to help people. Do you remember when you took this decision? Was there some particular event?"
She is brought to speak about herself emotionally.
You do not say:
Me: "Oh cool, it must be hard".
She: "Yes it is"
Of course you can still recover from here (from almost anywhere if you know what to look for), but you get my point.

For flirting, I mean to accuse her sometimes. I read somewhere that flirting is basically accusation.

These are some concepts that I try to keep in mind.

Other general tips for the vibe:
-Speak loudly and slowly
-If there is an awkward silence. Embrace it. Learn to embrace awkwardness. Not every girl will hook easily.