Texan & Half ... yeah, as a parent, I've learned to just keep my mouth shut unless it's just general cheering ... "atta boy", "battle up there", "good job 20". I figure my son knows much more than me about what to do in a particular situation, so any 'sugggestions' I might yell out right in the middle of any critical situation is simply a distraction.
One of the guys I used to coach LL with would always say "Players play, Coaches coach, and parents just cheer".