It is a little like juggling and just as hard to remember all things to do when describing a character in a setting. So I decided to put the ones I remember all together in the same place. Not necessary to use all these, but necessary to remember them and decide which suits the plot.
Describe the physical details of the character. Avoid tired adjectives, e.g., hard eyes.
Describe their personality (in a specific way not abstract – rather than angry have her shouting at someone). Find interesting and original ways to describe personality.
Describe the setting. Build item upon item. One idea per sentence. Use the setting to show person’s feelings or personality.
Describe smells, tastes, sounds, touch as well as sight.
Using possessions to aid characterization. Showing a person with their possessions can show more about them and their story.
Put characters in situations – mundane and powerful – can build up a picture of them.
Create a history for your character (there is a list of questions in Project 6 to help you).
Maybe give your character a secret (ideas in Project 6).