IMHO, try composing in your ear and head a complete song without any instrument. That's all the parts. A completed song as you hear it without picking up or using any musical instrument. Then put that down on tape (Sonar)
To do this you have to KNOW the song before you start recording and it's been my experience, at least for me, the music is much better and original. It's like doing a cover tune but no one but you has ever heard it.