Butterfly´s

1. first we create the large part of the wing
   to do this, create a wavy line with the path tool
   the length doesn't matter because we can scale it
2. then create a curved line from the top point downwards to make the head with a corner point
3. continue with the body downwards to make the smaller part of the wing

a template can help well here but only as a guideline because otherwise it is tracing. ok for your own use but for no other use