There is no best way!
In all honesty this is not a question that should come up unless you have plans to live together or you feel the relationship is heading into becoming "exclusive". Credit scores are on a "needs to know basis".
You shouldn't give out yours or ask for another's unless you're considering buying something together that requires credit scores.
I would file this question under the "Don't ask on a first date." for sure.
Too often these days people put the cart before the horse in an effort to "eliminate people" without investing time getting to know someone.
They've forgotten that dating is supposed to be a FUN social activity!
Enjoy the dinner, the movie, the play, the concert, the festival, the picnic or whatever and discover each others likes and dislikes as well as determine if you have any chemistry before you start swapping Fico scores! Dating is not a life and death mission!
No one is asking you to decide on whether to cut red wire or the blue wire. It's just a date! Save the interrogation questions for later.
Even if you ask the question there is always a chance that they'll either not know their score or give you a higher number than it is.
Whenever two people are attracted to one another they'll generally bend over backwards to impress each other. It takes few months or longer for most people to reveal their "authentic selves".