How to describe characters' physical appearances.
Introduction
Have you ever pondered why we use the word “character” in two wildly different meanings? An author will usually use this word to mean “a fictional person depicted in a book, movie, or other work of fiction”. In everyday speech, however, when one speaks of a person's “character”, one refers to the personality exhibited by that person.
That's… weird, isn't it? The same word can mean either “personality” or “fictional person”. How does this make any sense?
I strongly suspect that a fully substantiated answer would necessitate a thorough analysis of ancient Greek theatre. For the sake of brevity, I'll give you a different explanation—one much more succinct, yet (IMHO) no less true or profound. That being:
The reasons that characters are called “characters” is because their personality is by far the most important thing about them.
When appearance doesn't matter
Having established that, it is time to get into the crux of this article: characters' physical appearance.
I've read about, and also personally witnessed, a common mistake made by beginner writers: Spending too much time describing how their characters look. Their hair, their eyes, their height, the shape of their face, those are all lovingly described… and readers really couldn't care less about any of those things, because they don't help one whit in creating a vivid picture of the character in their head. But why don't they? Why does a character's physical appearance not evoke said character in the reader's mind?
After the introduction, the reason why ought to be blindingly obvious: None of those things hint towards the character's personality. Readers want to get emotionally invested in your story, after all, and nobody can get emotionally invested in characters' looks! What readers want to know instead is: what makes your character tick? What motivates him/her to take an active part in the plot? What are his/her weaknesses, insecurities, vulnerabilities? Secret and/or unfulfilled desires? Background experience? World-view? If a character is introduced as (eg) “a grizzled veteran, gruff but kind, determined to right a big mistake he made a decade prior”, then the readers already have very good reason to be emotionally invested. In contrast, if the exact same character is introduced as having brown hair and beard, black eyes, medium height, indefinable accent—sorry, I already lost you, didn't I? You get the point, apologies for making you yawn.
Another way to think about this is: Two identical twins can be completely different characters. What separates them is, of course, their personalities.
When appearance absolutely does matter
And yet… sometimes one's appearance does, in fact, give insights into one's personality, doesn't it? The gruff and unkempt oldster is probably not vain, or overly concerned with others' opinions. The wiry and muscular man is probably not lazy. The immaculately-dressed woman who always wears a particular old and weavily worn-out piece of jewellery is probably fond, not just of it, but the person of whom it reminds her.
Even more useful information can be gleaned by going beyond appearance per se, even just by a first impression. Off the top of my head:
- What does s/he sound like? Erudite yet insecure? Loud and overbearing? Quiet yet domineering?
- How does s/he posture/move/fidget? Does it indicate confidence or insecurity? Bravery or cowardice? Frailty or strength? Does the feeble old crone use her cane to stand straight even in the presence of royalty? Does the criminal's feigned indifference betray fear? Remember: the phrase “limp-wristed” describes personality.
- What are his/her expressions like? Does his/her smile reach his/her eyes? Does s/he hold others' gazes? If so, is it with inviting friendliness or with brash arrogance? If not, is it with craven guilt or with unfamiliar discomfort?
- What does s/he smell like? This is particularly of note when trying to establish sexual attraction. But maybe it's just that a faint whiff of nail polish remover in somebody's breath is a sign that s/he is trying to become more healthy.
- How is s/he clad and shod? Are the clothes old but neatly put? Maybe the person is supposed to lead a very physical life, but wears a uniform that is conspicuously new and un-worn?
Of course, you neither need nor should mention all of those; pick and choose the most evocative ones, and describe just those. Please note, however: in the above list, I made sure to high-light whenever two first impressions appeared to contradict each other. I whole-heartedly recommend that you do like-wise.
“Wait, which one's Turner again?”
For the sake of completeness, permit me to mention here a related mistake I've seen: Namely, when authors start using several characters' names to describe what each one is doing, without first bothering to establish who is who. The only time when this is permissible is when we're seeing things through the POV of a character that has the same issue with remembering everyone. In all other cases, care should be taken to establish each character first, so that a reader can form a strong mental image and connect it to the name.
When all else fails…
…just write a list at the beginning. Seriously! If the problem is that I can't remember who's who, I can look them up as the story progresses. If the problem is that you reeeeeeally want to describe all your characters physically, isolate the descriptions in one narration-free place and knock yourself out—that way, readers who don't care can just skip them.
I mean yes, I do realise that character lists have fallen out of fashion. I also realise they're more of a band-aid than a solution. But maybe a band-aid is all it takes for your case.