Although melodies are composed of individual notes, we experience them as shapes or movements. Because of this, it’s important to think of the overall motion you want to express through your melody. The rise and fall of a melody reflects the inflection of the human voice, even if it is only played by an instrument. A rising shape generally communicates a question, a climb, or a build in intensity; while a falling shape communicates a descent, a return to rest, or finality. 

When creating a melody, think of the shape that best reflects the idea or feeling you wish to express. If you are writing a melody for lyrics, it can help to mimic the inflection you would use when speaking them.