Find people who think like you and stick with them. Make only music you are passionate about. Work only with people you like and trust. Don't sign anything.
I don't think anyone has exhausted the range of sound possible in a conventional rock band, but people do become slaves to their own easiest techniques.
A more important reason is that the bands will intuitively trust someone they think is a peer, and who speaks fondly of the same formative rock and roll experiences.
By now all rock bands are wise enough to be suspicious of music industry scum.
We have no general conceptual thrust for the band, other than trying to make music that keeps our interest. When things are novel, they are probably things we have discovered by accident or investigation rather than by design.
If the label presents them with a contract that the band don't want to sign, all the label has to do is wait. There are a hundred other bands willing to sign the exact same contract, so the label is in a position of strength.
Doubt the conventional wisdom unless you can verify it with reason and experiment.
There is a lot of use of ProTools in professional studios, but this is mostly for the special effects it allows, not for sound quality. These special effects soon fall out of fashion, and I don't think this trend will define studios permanently.
Many rock musicians are excellent cooks, I've found, and those that are prefer to eat their own cooking in the studio. I encourage this behavior as I also enjoy the benefits of fresh food.
Make no mistake about it: once a band has signed a letter of intent, they will either eventually sign a contract that suits the label or they will be destroyed.
The woman I am currently crazy about was a vegetarian for a year until I started dating her. As is the case with most vegetarians, she had never eaten properly prepared meat, only commercially packaged or otherwise abused flesh.