Free writing.

Look at this photo.

I want you to write about what the photograph suggests you.

Write nonstop for a set period of time (8 minutes).

Do not make corrections as you write.

Keep writing, even if you have to write something like, "I don't know what to         write."

Write whatever comes into your mind.

Do not judge or censor what you are writing.

"Free writing is a prewriting technique in which a person writes continuously for a set period of time without regard to spelling, grammar, or topic. It produces raw, often unusable material, but helps writers overcome blocks of apathy and self-criticism. It is used mainly by prose writers and writing teachers. Some writers use the technique to collect initial thoughts and ideas on a topic, often as a preliminary to formal writing. Free writing is not the same as automatic writing."
(Source: Wikipedia)