If it's new code, and you are unsure what abstraction is needed, build the simplest abstraction possible. YAGNI That way, as the code develops, and it becomes

If it's new code, and you are unsure what abstraction is needed, build the simplest abstraction possible. YAGNI That way, as the code develops, and it becomes more clear what is needed, then you can easily build it at that time. If you have code that needs to be duplicated, throw it into a function, a lightweight and powerful abstraction.