Make everything about you
To make it seem like you’re happily in love with another live human, it’s absolutely critical that you make yourself the primary subject of any person-based Instagram you ever post. This may seem counter-intuitive, because you’re already desperately alone. That’s the whole problem, really. But consider this: if you never, ever, post a photo of your significant other -- ever -- no one can possibly prove that he/she doesn’t exist. Whoa. That’s some Schrödinger's cat logic chicanery, right there.
This is also a thinly veiled metaphor for living in New York City generally. And social media. And dating. So, yeah: everything is about you. Got it?
Shoot a sh*tload of landmarks
When your goal is to imply the presence of another person right next to you (despite the grim reality that you may never personally enjoy that basic human pleasure again), it’s crucial to Instagram yourself doing activities that single New Yorkers would never bother suffering through.
Quintessential, cutesy "New York rom-com" things to do together (walking the Brooklyn Bridge, sunbathing in Sheep Meadow, riding bikes up the West Side Highway...) must be Instagrammed, and why not? If you have a trusted emotional & intellectual equal with whom to experience the many small pleasures of this fair city, wouldn’t you? Yes, you would, and despite the fact that you currently have no such person, you should.