Carving the wings is easy.
Make cuts on the top and sides of the melon to make the feathers. We cut nested 45 degree cuts in sets of 4 or 5. This is best explained by looking at the photos and viewing the attached video. Make sure not to cut in too far, otherwise the wings will lose their structures.
Watch me carve the wings:
You can make a more complex swan (as I have done in the front page photo) by adding more sets of wings to add interest. You be the judge of this as it may depend on the size of your melon.