Find symmetries
If it walks like a duck, quacks like a duck then it is a duck.
Finding symmetries is a very important design concept in producing simple, elegant and robust software.
It’s another way of expressing the concept that removing features reduces complexity.
Examples of this are:
Not using websockets for server to server communication with setting up a grid framework.
The Lua language which doesn’t have arrays and tables - it merely has tables.
NodeList and HTMLCollection objects in Javascript should be arrays but are not.
Or sorting out your tupperware drawer - probably the most accessible way for a broad audience to understand this concept.