Character Descriptions
I have a friend (Hi Tara!) ask me recently about writing character descriptions. Specifically: How do you describe people without it seeming all fanficy?
So here's everything I told her, but with more detail.

1. Never use the mirror method to describe your MC. This one feels like it should be self-explanatory. I forget how many years it's been now, but this was a rampant tactic used by a lot of budding writers as well as a few who were already published authors. To those of you unaware of the trend, let's just say: do not have your character stand in front of a mirror and describe their porcelean skin, auburn hair that drapes down their back, or green eyes. Just don't.
2. I like to describe characters as they show up OR in relation to other characters.
Either a character comes into the scene and your MC has a moment where they take note of the person and how they look today, or they see a person and automatically begin to compare them to themselves. Both are good, more natural ways for a character to be seen and fleshed out.
3. Let the details come out in the scene.
Unless your MC is a cop and they often assess people based upon if they need to put out a BOLO, please do not describe characters as: _____ was a black male, early twenties, black hair, brown eyes, about six foot, weighing two-ten, and wearing blue jeans and a grey hoodie. Not only is this boring, but it's info that the eyes will skip over, and people will still forget what this character looks like.
Instead, allow your MC to take note of things organically. Is the other character's hair a snarling rat's nest of red hair? Do their eyebrows not match the obvious blond dye-job? Are there really too many piercings on that one eyebrow? Some of these will take some surreptitious glances to figure out. In the meantime, action can occur between the shedding of detais, so that it's not an obvious info-dump.
4. It's okay not to hit every mark. Hair, eye, and skin color is good. Height can be added if it's important or later on if it becomes relevant. (Like a teen boy's growth spurt.)
When you glance at someone, what do you notice first? That should be the first thing you describe. If you happen to enter a room and there's a really tall person in there, then that would be the start of how to describe them. You'd notice their height, then their body mass (muscular, heavier, thin as a rail). That's because your brain subconsciously dictates the threat level of a person. Tall and muscular typically get flagged right away because their ability to overpower you is of higher consequence than hair, eye, or skin color. However, if it's a scrawny guy around average height, you're less likely to pay attention to that. Therefore you'd latch onto facial features. But only the ones that make an impression. Beautiful green eyes? Large, hooked nose? Long hair or super short hair?
Of course, we won't pretend that skin color isn't one of the first things we notice if it's different from our own. (Let that sink in.) A person of color who lives in a neighborhood with other POC isn't necessarily going to notice all the brown skin tones, unless one is a little off. Either super dark, super light, or white af. Other than that, everyone is brown. (Not coffee brown. Not cookie brown. Not espresso with a little too much cream. Not milk. Not hazelnut. We are breaking the skin color=food description generational trauma.) The same is true of a white person in a predominantly white neighborhood. We'll notice the differences right away; not so much the similarities.
That said, if you introduce any character of any race, describe them. Even if they're white. Too often, caucasion is the default race of the MC, so the author doesn't often think to describe it. Let's not only get in the habit of changing that, but also making it clear even if they are.
A really good resource for writing skin tones is the site Writing With Color. It has words and combos even for hair color, eye color, etc. I highly recommend checking it out.
Now I offer you a quick example that I had to come up with at 8:30am to explain what I meant.
*
My mom walked into the kitchen, running her fingers over my shoulder as she passed with a sleepy, "Good morning, baby."
I rolled my eyes, but watched her discreetly as I ate my cereal. There were dark shadows under her eyes, and the makeup she used to cover them only made her pale skin whiter. Her light brown hair had been gathered into a hasty knot at the nape of her neck, instead of twisted up into some elaborate, professional style. As if that wasn't bad enough, her hands were shaking from caffeine withdrawal. She'd been main-lining coffee for two weeks now. Whatever was going on at work had officially hit the 'it'll get worse before it gets better' stage.
Ada bounded into the room with all the energy of a twelve year old on a sugar high. As a sleep-deprived teenager, I took full offense.
Maybe that wasn't the only reason I sneered at my little sister. I didn't bother to pretend I wasn't a little jealous of her. Not only was she a perfect replica of our mom, but she lucked out and got her dad's bright blue eyes instead of Mom's hazel. It made her look angelic, even if her actions more closely resembled Lucifer than Gabriel.
I, on the other hand, resemble my dad–which wasn't great considering the things he'd done. My skin was a light brown and my hair was black. I had his entire face, which still made my mom cringe in low lighting. But at least I got his eyes. Ooh, boy, at least I got the eyes.
They were a golden brown that looked like molten honey in the right light. And with the right eyeliner, they popped so much that even a glance from me could make a boy–and some girls–lose cognitive function. Still, I wouldn't have minded looking more like my mom, all things considered.
*
Note that this description doesn't just give you some idea of what the three people in this scene look like, but also what they're going through. The mom is a Caucasian woman with light brown hair and hazel eyes, but she's also sleep-deprived and stressed like crazy, meaning her composure has tanked dramatically. Ada is a preteen who hasn't caught onto the obvious strain, and she looks just like her mom, but with blue eyes. We also learn that Ada and the narrator do not share the same dad. The MC's dad is a man who we know has brown skin, black hair, and honey brown eyes. All of which his child inherited. He's also, by all known accounts, a crappy person.
You're not just figuring out how people look in this scene. There's subtext, emotion, and innuendoes. Everything you learn physically about a character is something that comes to light organically.
Now, these are with people the MC knows well. If it came to meeting someone completely new, it could look something like this:
*
I glanced up from my phone and had to do a double-take. It took me 0.08 seconds to realize what Vera was talking about now. The new kid was hot. Even if he was ugly, the fact that his skin was a medium brown but he had crystalline blue eyes would have made him an instant superstar in my school. Already, some tiny feral portion of my brain had taken one look at those eyes and gone, "Mmm. He make pretty babies. Me want." I shook the thought away and pretended to go back to my phone. Glancing surreptitiously at him as he passed, I tried to evaluate him more objectively and decided that I was right the first time and he was still hot, with or without the eyes. His face didn't have a lot of baby fat, so it made his features appear a little more chiseled than usual. His skin was clear of acne or noticeable scars. And if it wasn't for some crookedness in his teeth, his face would have been obnoxiously symmetrical. Beyond that, he was on the lean side, but his shoulders were broad enough that I pegged him for a contact-sport junky. Weirdly enough, he also had really great posture.
Unconsciously, I straightened in my seat. How often did I slouch like that? And why couldn't I make myself sit up straighter?
*
See what happened there? You got more detail in a condensed version because it was more relevant to the narrator/scene. Now, if the new kid hadn't been attractive, you'd've gotten nothing more than build, skin, and hair color probably. Because it's not as significant to the character–or the reader, for that matter. What's also funny here is that the MC noticed that he was a) attractive, b) figured out what made him attractive to her, and c) clocked something unusual about him and immediately started comparing herself to him. The scene, in this tiny format, is focused on the description of another person, but it doesn't devolve into the MC being instantly obsessed with him. Instead, she clocks the attraction and then goes right back to thinking random thoughts, as teen girls are wont to do. If you really struggle with this, maybe start describing your friends/coworkers/acquaintances in your head to get in the habit of identifying what you first notice as well as what stands out to you. Remember, you don't have to describe someone down to their dimpled chin and acne scars, but certain things stick out and that's what's important. So, there you have it, my best advice as far as layering in character descriptions when telling your story. No APBs. Just randomly noticing things about people as they come into your orbit.