But in some situations–for example ... wanted some breadboard setups for students. I did end up make a simple PCB that plugs into a breadboard, but looking back the simple circuit would have ...

You can see an excellent example of breadboard-as-art on the cover of “Analog Circuit Design ... with an LED bar-graph IC that shows students the difference between a linear and a non-linear response.

However, you can also pick from a number of predefined circuits ranging from the simple (a voltage divider, for example) to the illustrative (a PLL frequency doubler comes to mind). There’s even ...