KIS (stands for Keep It Simple) relates very much to the previous point. When you are designing a software component, avoid over-engineering it; ask yourself if your solution is the minimal one that fits the problem.
Implement minimal functionality that correctly solves the problem and does not complicate your solution more than is necessary. Remember: the simpler the design, the more maintainable it will be.
This design principle is an idea we will want to keep in mind at all levels of abstraction, whether we are thinking of a high-level design, or addressing a particular line of code.
At a high-level, think on the components we are creating. Do we really need all of them? Does this module actually require being utterly extensible right ...
