Writing descriptively involves describing a setting, a person, or even an emotion. Writing a description allows you to fully engage your own imagination and that of your reader. Being restricted to the written word when evoking a three-dimensional, multi-sensory environment is a challenge, but, as you know, good authors can do precisely that. The key to writing a good description is to make full use of the English language and to think carefully about choosing exactly the right word for the impression you'd like to convey.
Try this English quiz to see how much you know about descriptive writing.