Experience gives us a better chance at guessing solutions to a problem.

For instance a 220 Ohm resistor is a good rule of thumb for an LED current Limiting resistor in a 5 volt circuit.  A simple guess for a 10 volt circuit would be to just double the resistance to around 440 ohms.  Unfortunately this will probably burn out the LED.  From experience of doing the calculations, you would recognize that a 1000 ohm resistor usually works well in a 10 volt circuit.

Heuristic method comes in to play when you are working in an area that you are less experienced in.  You look at how similar operating circuits have worked in the past and make an educated guess to design the new circuit. Sometimes you just make a guess and then test, even with no reasoning as why that guess would work.

So if you are a tinkerer or an engineering student, go get some experience. Go build some circuits, make some changes, break something, then try to fix it or maybe improve it.