If your goal is to do the highest quality body work possible, there is almost always one big hurdle, time. So, how can you produce the level of work desired in an acceptable amount of time.
The reality is practice. Lots and lots of practice, learning as much as possible along the way. Your mindset must always be set on getting better.
Another way is being methodical with what you’re doing. A lot of these tips are part of that. Things like establishing one ‘straight’ surface first and building off of it. Getting the body straight, then dialing in the body lines, then dialing in the gaps. Getting the panels set properly in bare metal and using long flat stock spanned over the body to show you where the edges need to be. Using that flat stock to check your body work, a lot. The primer sanding steps. Using guide coat while wet sanding clear coat.
All of those items are for a reason. They produce quality results, in the least amount of time, and have been figured out over thousands of hours of practice and experience.
Doing high quality and thorough work, paying attention to the small details, and being methodical will help keep you from going backwards and re-doing steps.