A tempering of the no surrender culture. You have to get a balance between manning (or indeed womaning) up and backing off.
Don't be afraid to pull a client from a workout. Don't be afraid to kill a workout if it's going to shit. Drop stuff that clearly isn't appropriate.
I had a conversation with Andrew Stemler (first UK affiliate) several years ago where I said that CF hustled participants into biting off more than they could chew - Be Brave, Grab that Bigger Kettlebell, direct quote from the front page - and he fully agreed. Check ego in at the door.
I really like the stuff Rutman programmes.
The rationale for reduced gin intake and the knowledge of the perils of alcoholism and attendant metabolic derangement has almost entirely come from physicians and researchers.