I agree that writing unfamiliar pairings is a good thing. (At the moment I am writing Sho/Ohno/Jun and I always swore that I would never write Yama ever.)
I love writing Nino (usually as Matsumiya) because of his vulnerable side. Something that I am exploring in the Wings drabbles that I have been writing recently.
I think that I just need more practice at Sakumiya (maybe the Arashi Exchange?)
Thanks and *hugs*