I've always tried to have specific commands for various behaviors so the dog doesn't get too confused by what I am telling him to do. Just saying "NO" doesn't really tell the dog anything and may confuse him as to why you are hollering "no" at him.
I use the command "leave it" when there is something I want a dog to stay away from. My dogs understand that "down" or "get down" means to put four feet on the floor and get off of me or the bed or whatever, while "go lie down" means to bug off and settle down somewhere away from me, and "drop" means to hit the deck in a lying down position (for advanced obedience training). For unwanted barking, it is "quiet" or "be quiet", in a very loud, demanding voice.
If someone is growling (usually toward another dog), I loudly say "KNOCK IT OFF!" as I stare holes in the offender.... and I have been known to growl back as I stare holes in the offender (usually a very crabby bitch I have here who doesn't want to share her *very large* dog pillow with anyone else).
Our back dog area is huge, with woods, fallen trees, etc., and the dogs MUST come in when I call them. My dogs are trained to come to the voice command "come" and to my long, loud whistle. They usually come in running, and in a very upbeat, loud, voice, I will say, "YAY!!! WHAT A GOOD DOG! GOOOOD COME!!!! and as they come running in, I sometimes will also excitedly clap my hands. It does help that the older dogs train the younger dogs that coming back inside is a good thing. NEVER correct a dog for coming to you!
Karen Brittan
Britmor Schnauzers