Excerpt from my story:
"You don't control me, Emperor,” he growled, rubbing at the glowing Mark absently. It flared slightly at his defiance, and he growled a curse before tugging the brace back on. He tightened the straps with his teeth and flexed his fingers, then stood and strode over to the wash basin. A bearded man stared back at him from the water, grim-faced and determined. The image shattered as he plunged his hands into the basin and scrubbed his face, memories still swimming before his eyes. His shoulders trembled with anger as he gripped the edges of the table, taking deep breaths until he was able to push the images out of his mind.
Later on I have a different char mention that his hair is brown and his eyes are green.
Don't say "he had brown hair and green eyes."
Be descriptive! "The wind tugged at his hair, making the brown locks dance with the breeze. " How does he react? Does he notice and brush them away in frustration? Or is he absentminded and oblivious?

In story I like to describe characters as little as possible, concisely, and where relevant. If a character gets hit on all the time we can assume they are attractive. Everyone has their own idea of what that is. If we want to deceive negative traits have other characters react. Be repulsed, insult them, be awkward. If a character insults another and they insult back that's a 2 for 1 description: "who you calling fat? You're not that far behind me." No one cares Guy Sadsack is 6'5". We aren't tailoring his suit. Simple things like having only one character be able to, or not able to reach something on a shelf for instance, or struggling is enough to give us a general idea. If it isn't relevant to their character or the plot in some way cut it. Unless Jim Plankton's signature is his cool eyepatch, or Susie Rottencrotch depends on our knowing of her huge feet to understand her or set the scene- leave it. Most descriptions come naturally. He's lost in her <hazel> eyes....

Her toned muscles poke out from beneath soft lines of her skirt as she makes the jump, betraying she likely isn't just another office temp. The children ran from his disfigured face, his teeth exposed through the flesh that had peeled away from his jawline, like something they'd see in a nightmare- only real, and dangerous. He pulled his hair from his eyes and bound it in a tail with a cord of leather so that it wouldn't interfere. We can acertain certain details. In the above I didn't mention his hair was long, or how long. Obviously we know it was long enough to be made into a tail, and long enough to get in his face otherwise.

How do you describe characters? Don't. If it's important to the plot, it will come up naturally, as the other replies have shown. For most stories, it doesn't matter if a character's eyes are blue or green and having those descriptions can feel incredibly boring and contrived. Of course there are some genres that lend more towards descriptors; a human meeting aliens in a sci-fi setting would almost definitely remark upon their grey skin and 3 arms. If you feel the overwhelming need to describe your characters, then find creative ways to do it. Have them fill out a dating profile, have someone try to find them in a crowd, have a friend describe them to a stranger, etc.

You could also just briefly summarise the character in a single sentence, covering the most visually attracting points. An example from one of my works:
"The next day, absent from his usual service, Tyron spent his time watching over the arena, as the combatants, the likes of which often changed on a daily basis, were fighting for the right to one day challenge him. That was, until a newcomer of a very unusual kind drew his attention. Dressed in clothes tinted yellow and purple, with a violet scarf streaking across his neck and covering his face, and armed with only a simple, barely decorated glaive, he joined the ranking ladder for that day at the last second."
That gives you the brief visual of the character, and things like attitude and personality are always better expressed through actions in the story.

That's actually how I do mine come to think of it.

"And then there's this bitch"

Usually physically I do top to bottom or bottom to top, or the most noticeable part first. Describing their personality, pick out their most prominent feature.
Just in general I find the “Who what when where why” helpful. Make sure you cover most of those in your first page/chapter

Also, if you want it to be clear that a character is a certain race or such without description, you can convey a lot through their name

If you want a simple out say something like "(the love interest) studied his/her features, their blue eyes and soft brown hair felt conforting" type thing

Comforting*