While there are some obvious ones, much of the genius of the show and Falk is that you can't often tell when he does it or not. Bochco explains it so well here at the 7-minute mark: https://www.youtube.com/watch?v=O2wOnLS7lqc
I'll keep looking for them though...

Almost every actor in Last Salute For The Commodore seems to be doing a little.