I just find it strange that there can be an apparent need in such a vital part of human existence and yet nobody has figured out what to actually do.
In general I recommend people to work with the garage door open, and to actively interact with people on local online communities. I forgot who wrote that a blog post is a search query for like-minded people. I met a ton of people through my personal website and social media activity.
I don’t recommend general purpose meetups as they tend to graduate quality people quickly and leave behind a lot of weirdos that tend to form the core of the attendees. It’s also hard to meet strangers when you have nothing in common.
Note that all of these methods require you to be a genuine participant. There are no shortcuts to meeting people, and thus no shortcuts to meeting potential partners. People who try to find shortcuts ruin communities and force them to put up fences.
Another thing is to not to "wait for Godot" by passively waiting for others' initiative and instead be the source of initiative by default.
Finally, PSA: don't buy into any of the immature objectification, stereotyping, or egotistical nonsense... be real and treat others as human beings, not a means to an end.
“So, your kids must love the iPad?” I asked Mr. [Steve] Jobs, trying to change the subject. The company’s first tablet was just hitting the shelves. “They haven’t used it,” he told me. “We limit how much technology our kids use at home.” (NYtimes article, Sept. 10, 2014)” ― Nick Bilton
“Technological progress has merely provided us with more efficient means for going backwards.” ― Aldous Huxley
Interestingly, though he didn't intend it (he thought he was writing dystopian fiction), Aldous Huxley actually predicted humanity's best possible future with "Brave New World".
Without traditional (basically pre-technological) societies where women are essentially slaves, people earnestly believe in ridiculous supernatural religious claims, and couples are basically stuck together no matter how miserable they are, it's simply not mathematically possible for birthrates to be kept high enough to sustain the human population. Huxley brilliantly predicted a future society that could use technology to solve this problem which we're now seeing in developed nations. Societies should be looking at it as a blueprint, not something to avoid, though the constant drug-use should probably not be emulated.
It may have provided us with the largely unused means to more easily go backwards if we want to (for example, via nuclear or massive biological war), but the idea that it's made us worse off from some ideal previous state of lower technology is popular, fashionably nihilistic nonsense with no bearing on concrete reality. It was also just as stupid an idea in Huxley's time.
Anybody who thinks such a thing should really read more carefully on how nearly every aspect of life was in the past, even fairly recently, or if they have the means, go visit a society that today genuinely lives without using modern technology.
(pseudo-hippie communes of "like-minded" individuals that back up their cute experiments with modern industrial products, modern medicine and the ability to go back to civilization at any time, don't count)
Also, a declining population doesn't just mean "go back to a more sustainable level". It's not like people are suddenly going to start having babies again when the population gets to, say, 1B, and things will carry on sustainably. Instead, there'll barely be anyone who can have babies, because everyone will be elderly (i.e. inverted population pyramid), so the population will just keep collapsing. And with so many old people needing care, and no young people around to do it, things are going to get really bad quickly.
People seem to think we're going to invent some super-advanced humanoid care-giving robots "any day now", and I suppose also invent some way of people being able to have more kids over a longer lifespan or something, but betting your society's future on uninvented technology is not good planning I think.
How do you think wars are going to be avoided when there's a demographic collapse? With so many old people and so few young people to support them, something's going to break. People don't normally just put up with failed economies; wars are a frequent result. Famine is also a strong possibility: the elderly people probably aren't going to be doing all the farming, but they still need to eat.
People who talk about population reduction as a good thing always seem to assume that the demographics will be similar to today, with plenty of young people to balance the old people, and that's absolutely not what's in store.