Short description:
Have a business explanation of the things done in the recipe when you hover it. (so we don't need to open a recipe to understand what's happening or where is the root of an error)
Clear title:
Short text explaining why this recipe is needed and what are the expected outputs
Comment every step of the code
(keep in mind that everyone should understand what the part of the code is doing)
Functions:
Respect the pep8 convention (details what is in input and also expected outputs), you can store all your functions in a dedicated Library.
Units tests:
Regroup the units tests in a zone of the flow, here’s the documentation.
Global documentation: here