Whether it's rec ball or travel ball, before we take the field for our first practice I always hold a mandatory meeting with parents and players to discuss parent and player expectations for the upcoming season. As part of my speech I let the players and parents know that the umpires are doing their best but they will still miss calls that will hurt us and they will miss calls that help us. But under no circumstance are parents or players permitted to berate or abuse umpires.
In travel ball my penalty is that the player is suspended for the next tournament - even if it's the parent(s) of the player that are being abusive. There is no second warning. If it happens again the player is off the team. That may seem harsh, but I remind parents that their behavior is setting an example for their player.
In rec ball I can't cut a player, but I can sit him on the bench. Our organization is actually really good at disciplining parents. I've seen more than a few permanently banished from the ballpark.
As a coach, I've never become animated with an umpire. I've questioned calls and even lodged a protest or two, but never blown up at an umpire. I don't see the purpose. As a parent in the stands I've never lashed out at an umpire, either. Parents that do things like that tend to upset their team even more. Kids are great at letting it go. On my teams we teach the kids the phrase, "Next play!"
Over the years I think I've earned the respect of the umpires and while part of that is my demeanor, another big part is that I study the rule books every year be it USSSA, Top Gun, NFHS, Dixie, and local rules. And I will admit that my knowledge of the rule books has pissed off an opposing coach or two over the years as well 