I don’t know that I have any tips to add to this list. I try to push my abilities to the limit, so my methods are generally direct and somewhat random. Though I don’t believe so much in randomness, I believe in the power of synchronicity.
Anyway, what I usually do is just go out and do things, and strike up conversations with people wherever I go. My aim is to meet people out of the blue who I would otherwise have no reason of meeting or running into, and getting to know them from basically nothing. If the person then turns into an acquaintance of some sort, great. If not, also great. I’ve sharpened my skills, pushed my boundaries, faced my inhibitions, and brought more connection to a world that is becoming increasingly more disconnected (at least IRL, not speaking of online). I’ve had some of my most fun times and met some of my best friends this way. And I feel like the skills it offers me are more flexible, and most importantly, it tempers my psychology in a way that makes me more resilient and willing to face challenges.
But it’s also not incredibly effective for making lasting connections. As I said, I’ve made several friends and gotten into many exciting adventures this way, but it’s still been somewhat limited overall. I think your methods are far more effective for making a greater number of connections and having them last. I think there is merit to both methods.