Your subject and your purpose should determine the way you organize your ideas. If you are narrating a story, for example, you will want to put the details in chronological order. If you are describing an object or a person, you will probably use a spatial pattern.
The main patterns of organizing information are:
Chronological (by time)
Spatial description (by location)
Classification (by category)
Illustration (by example)
Argumentation (assertion and support)
Compare/Contrast (whole vs. whole or point by point)