When you are reasonably satisfied that you have all the instruments and parts you need to finish your song, it's probably a good time to step back and listen to what you've created so far. Take a moment to ask yourself if you like the way your song is put together and the way it progresses from beginning to end.
When you start thinking about how you want all your parts to fit together, it's time to start arrangingmaking decisions and reconciling what you set out to do with where your song seems to be going.
Once your song is arranged, you can begin mixingadjusting parameters of each part so that they better complement one another. Then you will master your final stereo mix and burn your polished song to a CD or save it as an audio file.