First off, take yourself seriously. Writing personal essays isn’t easy. We get called shallow for navel-gazing and all that, but it’s actually one of the hardest things in the world to do; to make thousands of strangers care about you. If you can do that, it’s a big deal.
The key to success is that you have to extrapolate at some point. Ask yourself how your story fits in with a wider narrative. The easiest way to do that is to come up with questions for your audience. Sneak them in carefully. “Who gets to decide who we are, ourselves or society?” Stuff like that.
Answers are informative, but they can sound like lectures. Narcissistic lectures too, since your essay is all about you. Questions are open. And the great thing about Internet writing is that discourse is now open to everybody. It’s the pinnacle of democracy, really. You want to invite as many people in as you can.
Corollary: As a rule, the more outlandish the topic, the more declarative you can be. For example, “I Had My Period On My Mother-In-Law’s Wheelchair And I’m Not Sorry” is going to get a lot of hits. Tone is important too. You don’t want to sound too dire. Except if your essay is about something severe: rape, mental illness, etc. Then you get to be as sharp as you want. In fact, you should be sharp about it. Otherwise you’ll sound cold.
Emotions are more important than analysis to most readers. I tend to get analytical about even the worst of my problems, but those pieces don’t get as many hits as the passionate ones. If your problem is more of a slow burn: getting older, losing friends, being stuck in a job you hate for the next 40 years- you’re supposed to make your readers laugh. Be glib. Society looks down on whining about problems everyone has, so you have to trick your readers into thinking they’re reading something funny. Then at the end they’ll be like “Damn, I felt that so hard.”
Remember, everyone wants to commiserate. But few people set out to do it because there’s a lot of puritanical guilt behind it. The Internet can sometimes feel like a giant competition of pain. But you don’t have to feel inferior to other writers just because you didn’t catch your dad having sex with your girlfriend in the middle of a collapsing coal mine. The most mundane problems can be as bad as the extreme ones. You might think someone with serious problems would be like “My breakup is nothing compared to my schizophrenia.” But it doesn’t really work that way. Pain doesn’t cancel itself out. It would be great if there were a finite amount you could experience, but there isn’t. Not having love and meaning in your life is one of the worst things that can happen to anyone.
And find your voice. Try to be unapologetic about it. Being unapologetically yourself is a big deal too. People don’t like timidity in writers. (Or presidential candidates.) I think that’s the most difficult part of writing a personal essay: not being scared. It’s the most important one though. Because personal essays are designed to make the world less scared.