The thing that makes cat’s cradle work is the balance of opposing forces. The threads can form a structure because they are held in tension by the separated hands. Bring your hands together and this tension is released, and the three-dimensional form collapses.
I find this a useful image for juggling the competing demands a song makes on the arranger. There’s a network of opposing forces in somewhat different dimensions, both technical and artistic, pulling on the arrangement as it develops. Depending on the song and the group who’s commissioned it, the demands will vary, but there will always be this sense of simultaneous, but conflicting imperatives.