 It starts with knowing what I 'm composing for . Is it a battle theme , or main title , or ambient theme , etc . Then I figure out what type of mood or style best fits ... the subject matter . From there it 's about picking the right instrumentation and then the writing process starts . It could start with anything ; a guitar riff , a French horn melody , a drum rhythm or bass line . Then I keep alternating instruments track by track recording one part at a time until I have something that sounds full and gets the point across I 'm trying for . 
