Pick a date, time, and location that seems sensible. Post a meetup. Say "I'm flexible about details, if this point in spacetime doesn't work for people". At the specified time, show up with something identifiable, and a book or some work that you can do to keep you occupied for, say, two hours in case nobody shows up. Hope somebody shows up.

Or feel free to say "I will only be there if I get at least N replies", where my own preferences would place N at one or two but YMMV. That reduces the probability of being bored and alone, but also reduces the probability of successfully meeting someone.