What most people seem to forget is that "best practices" are not universal: Depending on the size and scope of the software project, some best practices are actually worst practices and can slow you down. For example, unit testing and extensive documentation might be irrelevant for a short term project / prototype while they will be indispensable for code that should be understood and used by other people. Also, for software projects that have an exploratory nature (which is often the case for scientific projects) it's usually no use trying to define a complete code architecture at the start of the project, as the assumptions about how the code should work and how to structure it will probably change during the project as you get a better understanding of the problem that you try to solve. Trying to follow a given paradigm here (e.g. OOP or MVC) can even lead to architecture-induced damage.

The size of the project is also a very important factor. From my own experience, most software engineering methods start to have a positive return-on-investment only as you go beyond 5.000-10.000 lines of code, as at this point the code base is usually too large to be understandable by a single person (depending on the complexity of course), so making changes will be much easier with a good suite of unit tests that makes sure you don't break anything when you change code (this is especially true for dynamically typed languages).

So I'd say that instead of memorizing best practices you need to develop a good feeling for how code bases behave at different sizes and complexities (including how they react to changes), as this will allow you to make a good decision on which "best practices" to adopt.

Also, scientists are -from my own experience- not always the worst software developers as they are less hindered by most of the paradigms / cargo cults that the modern programmer has to put up with (being test-driven, agile, always separating concerns, doing MVP, using OOP [or not], being scalable, ...). They therefore tend to approach projects in a more naive and playful way, which is not always a bad thing.