Learn the music. Before starting to plot out the moves to your routine, take the time to fully know the music. You should memorize every crescendo, pause, chorus and musical refrain. You need to be familiar with the music in order to create the strongest routine possible.
Write your own story. Determine what story the music is telling you. Write down your thoughts, feelings, images and anything else that comes to mind when you listen to the music. You may hear an actual narrative with specific characters and events, a progressions of thoughts and feelings or even your own lyrics to the music. You may see pictures or scenes in your mind as you listen to the piece. Whatever you hear or imagine is perfectly fine; it's all about how the music moves you.
Record yourself going through your catalogue of moves and then watch the footage. As you review the footage, write down what feelings, emotions or narrative elements each of your gymnastic moves evokes.
Put the moves to the music. Now that you have determined what your song is saying and how your moves demonstrate those same emotions and narrative elements, it's time to put it all together. Assemble your routine like a puzzle, dropping in the physical elements where the music calls for it.
Record yourself doing your routine and see if you think the moves, once put together, still tell the story you were hoping to. Continue tweaking and refining, making sure to record and watch as your routine evolves.
Perform your routine for your coaches, teammates and friends. Get their opinions on it and ask them what the routine says to them. Look for the same emotions and actions that you felt to be conveyed to your viewers through your routine.