Following on the advice Mr. Young gave in his post on Almost an Author, go somewhere, inside or out, and study it for a full minute. If you are like me, it might take you awhile to clear your mind of all competing thoughts, but keep focusing until you can study a scene for a full minute with full concentration. Then take notes on what you see. Don’t try to write full sentences. Just write down your impressions as accurately you can. You can even make up words if that helps you capture the scene.
Once you think you have observed all you can, you can use your notes later to flesh out a properly written scene. Your notes are like a sketch an artist uses for a more detailed work.