If all resistors in the circuit were modeled by a single resistor what would be the effective resistance of the circuit

add the resistors in series, add  recprocals of those in parallel and then turn it upside down, then combine all of it.

series ... same current through each in sequence

parallel ... same voltage across each together

i guess that visual aids present persuasive examples to what you are presenting, some factors would be theme (does it fit with the color, information, what you are presenting), size (can you see it, is it a big enough span of data/information), and overall look of the visual aid.

hope this : )