Are there any guidelines and/or best practices for
staging car modifications?
I appreciate that there are local maxima, in terms of efficiency gained in any one area of intervention. And as you relax your tolerances from what is optimum, usually the number of ways to achieve that relaxed goal increases dramatically, which can allow you to optimize in consideration of other characteristics (make vs buy decisions; appearance; durability; outlay; BEP; etc.)... all the while, there are synergies that can only be realized if there's sufficient intervention (ex. lightweighting).
I come from a project management background and work in the healthcare sector. I have a good number of basic sciences and math, but no engineering experience. Being in medicine, my habit-of-mind is this: as much as I enjoy problem solving, the last thing I want to do is go completely clean-sheet when I know there's a lot of really smart people have put a whole lot more thought into these problems than I could in a thousand lifetimes. My time is generally not well-spent finding solutions to problems but spending most of my time figuring out which problems are most likely going to change my decision, and the expected range of risk vs reward from the perspective of multiple stakeholders.
So I'm looking for frameworks to help me gauge where I should best be spending my time because this is entirely a passion-project/hobby for me, but leisure time is sadly very scarce.