Characterization drives a story. Not only do strong and well-developed characters capture a reader's attention, but they also help to propel the plot. Part of good character development is describing the way a character looks. Creating a strong visual image for readers makes the characters seem more real. In some cases, aspects of a character's appearance can also inform the plot or the theme of a story, such as race, age or certain scars.
Use Concrete Examples
The best place to start with your character description is with concrete examples. Don't say that your leading lady is "beautiful" or "thin." Say that she has long, chestnut hair, crystal blue eyes lined with thick lashes and legs that jut out in knobby knees. Be specific. To say that a character has "brown hair" doesn't create nearly the image as saying that a character has long dreadlocks. Don't focus on just the obvious aspects of a character's appearance, such as eyes, hair or height. Think about what kind of clothes the character wears, whether a character has freckles or moles, whether her teeth are straight or crooked or what kind of scars he has. Avoid generalities and cliches.
Make Examples Do More
Avoid overloading your reader with a list of details about each character's appearance. To create a vivid image of your character without spending a lot of time on minutia, choose details that have a ripple effect on the description. For example, if you establish that your character is 80 years old, there is no need to spend a lot of time describing his wrinkles or his balding hair and other signs of age that will be assumed. Instead, make note of their absence, which would be unexpected. Other details that can have a ripple effect include a character's race or ethnicity, weight, hairstyle and body adornments such as tattoos or piercings. Just be careful not to slip into stereotyping.
Use Figurative Language
Sometimes, simple description isn't enough to convey a feeling behind the way someone looks. For example, describing a degree of beauty or the slight hint of sadness or despair in a person's face can be difficult. Using figurative language such as metaphor and simile can help you express that intangible quality that you can't quite put into words. Though figurative language won't quantify the description, it will convey a sense of emotion that will help readers better understand. You can describe a character as "having a smile that looked like summer" or "with a brow like storm clouds." A few well-placed details will bring together the image in the reader's mind.
Physical movement can influence the way a character looks. For example, your character may walk with a slouch or may strut with bravado. She may nibble daintily or tear into food with hedonistic abandon. He may make direct eye contact or move his eyes nervously about the room. The way your character moves paints a portrait. You can also use action words to describe physical features. For example, a nose can be "twitchy" and a mouth can be "playful."