Great post and thread! Here's my $.02 on the topic.
I have been on both ends of the spectrum. I was the punishment coach when I first started. I was 23 years old when I took over as a head coach, and to use a line from Bull Durham, I needed to "announce my presence with authority."
I had very specific punishments set up for every imaginable scenario that may happen. My code of conduct really amounted to a punishment schedule, as I had thought of almost everything a player could do wrong, and had a very specific punishment for it. I had lots of discipline issues, many of them arose from resentment that was created by running kids when they made mistakes off the field, and suspending them for any violation (according to my conduct policy). I was a yeller and screamer because I didn't know any other way to deal with the kids or how to correct their behavior in a positive manner.
Fast forward 12 years, and I am a completely different coach. My code of conduct is very vague, allows for flexibility, and consists of standards to be lived up to, not rules to be broken. We do not use conditioning as punishment, and only take away playing time (in the form of suspension) in the most extreme cases.
So how do I discipline? I talk to kids. When something goes wrong, I take the time to sit down with them, find out what is happening, and find out what we can do to correct the behavior. I guess my main for of discipline is conversation.
The change in discipline in my program has be tremendous. We have fewer problems with behavior on the field, we have fewer problems with behavior in the classroom, we have fewer problems with kids being late to practice, and we have a much more positive vibe in our program. I get emails, texts, and visits from our alumni over the past 6 years all the time. I hardly hear anything from the players in my first 6 years when I coached out of fear.
I have several of my former players come back to work out camps in the winter and summer. This past summer, one of them told me that I was the most "terrifying" coach he had ever had. I asked him why... I never yelled at you, I didn't punish you with conditioning. Why were you "scared" of me? He told me that he didn't want to disappoint me or the team. That's when I knew my discipline philosophy was working. He wasn't terrified of me as a person, he was terrified of letting me and his teammates down.
From my experience, punishments can change behavior in the short term. If you want a behavior to stop, sitting a kid for a game, or running them after practice can stop the behavior. But I have found that makes the athlete's main focus avoiding punishment. I want my players to strive for excellence, and to know that if they make mistakes myself and our coaching staff will be there to help them. I'm working with 15-18 year old kids, they are far from a finished product.
This seems "soft" to many, and when it is first implemented, it can be rough. Running a kid or sitting them takes care of the problem quickly. Developing a program on mutual respect, takes a lot more time and is more difficult for the coach. You have to be confident in your abilities, and at times, you will feel helpless.
I know this type of discipline isn't for everyone, but I am a much happier coach, the players get a better experience in our program, and the program has become more about the player than me.
If you are interested in my code of conduct, let me know and I will send a copy to you. We also have one for coaches and parents.