What's your rate on ways to find "the one"?

There are many ways to find a date, with people who you already knew like co-workers and friends; with people who you barely know and hit on with; set-ups; online dating and so on.
For those who are looking for serious relationship/ “the one”, I wonder which way would you try first, or which way do you believe is more possible to lead to a serious relationship?
Thank you for your attention. :)