I often find myself doing:
dig www.example.com @$(dig NS example.com +short | head -n 1)
It's a bit like doing a dig +trace www.example.com
but starting from the NS of example.com instead of starting from a root, so it's faster and less verbose, which I like.
I was unable to find a dig option (or another tool? a simplier way?) to do so, which I find strange, did I missed one?