When creating characters for your story, the most important thing is to have a sense of who they are as people. If you treat them like real people, they will jump off the page and be distinct to your reader, whereas dressing your characters up in gimmicks and crazy physical attributes in lieu of actual personality is a one-way trip to boring characters. A guy with a monkey sitting on his head is interesting for about a page-and-a-half. A guy who seems like he’s based on a real guy who happened to have a monkey sitting on his head is interesting for the entire story.
I have to start thinking more about these essays before I start writing.
Anyway, you still have to describe your characters, at least a little. At least upon first introducing them. And that’s difficult for some writers—what do you mention? If every character is described in the same way, that’s a problem, but you also want to avoid reducing them to the most obvious kinds of physical detail (skin color, eye color, etc). Here’s what I do: I imagine myself on a bus.
The Bus Trick
Most of my writing advice boils down to modeling everything on real life in some way, because I am a painfully lazy and literal person. The Bus Trick is simple: Think back to the last time you walked into a crowded public space filled with strangers. For me, a bus usually does the trick, but any venue where you met up with a few dozen total strangers will do.
Now, imagine the people who were there when you arrived. What did they look like? How would you describe them?
The details you come up with will be natural and telling, and can be re-purposed to describe your characters in natural and telling ways. Sure, you have to be aware of your own prejudices and assumptions here, but it’s still a great way to get authentic reactions, and a good way to ensure that you’re not describing your characters in the same way every time.
Just remember: When it comes to physically describing your characters, less is more. You will never do a better job than the imagination of your reader.