In music the concept of a motif is that of a short little chunk of music that you use to create a whole piece. It could be a short Melody, I read them, the chord progression, are just about anything else and music. You can hear this in the music of Beethoven and especially in his fifth Symphony. The first four notes are the motif that the rest of the piece is built from.
You can use the concept of motif in writing as well. Just start with the little chunk of writing and build from it. Example you can start from a word. you can start from a sentence. You can start for main topic. Just take a small chunk of riding and expanded, add to it, play with it, do whatever you think you can with it.
Using a motif is also a great way to come up with ideas. Find a chunk and play with it. Find a word and play with that. Pick a topic and see where it leads you. Hey, if it worked for Beethoven it'll work for you.
What do you think?