Besides the cabeceo and miranda some active socializing capabilities always are recommended in europe. Festivals in summer and near the beach offer a playful approach. Try to find the tango people among the crowd.
I usually attend milongas while I travel for work. Different kettle of fish (and not necessarily "unbetter". I find your apparent obsession with ranking experiences on a one-dimensional line with one "better" than the other quite baffling).
I sometimes travel with work and, when I get chance, sneak off to a local milonga in the evening. Sometimes I get a lot of dances, sometimes hardly any. So far I didn't sit the whole night without a single dance, but I'm sure it'll happen one day. I enjoy the process of 'getting known' at an unfamiliar milonga. It's a good exercise and it depends on a lot of luck. It's good to go back to square one once in a while...
Someone has to be willing to take a chance on you entirely on the basis of how you're sitting in your chair, and hopefully that turns out to be someone you can dance well with, and hopefully you will be noticed as being someone who might be nice to dance with by others in the room.
And the trick is not to spend that whole first tanda trying to get noticed by the rest of the room. Because I think that looks painfully obvious to everyone and is pretty disrespectful to the person who did take that gamble on you!