I've gotten the hang of solving block diagrams, i.e. condensing them to a transfer function. I'm aware that one may be solved in multiple ways.
For simple diagrams, it's fairly straightforward to see where the first "transformation" should be applied, and with which rule.
It's more difficult to apply this to something more challenging... to just go in order of the rules, i.e. first search for negative feedback blocks I can combine, then blocks I can combine in series, and so on. Or, for example, if both are present in the diagram, I can condense either area first or apply both rules in one step.
It appears daunting to "wing it" and e.g. move a branch before a block to see where it takes you, similar to Sudoku (i.e. we're only given guidelines, but because there are multiple ways to reach the solution, we should "wing it" and fill in an 8, even if it risks us going back from the beginning to try again).
From many tutorials I've seen, people mention the various rules, but no one ever seems to mention a step-by-step strategy to solving more difficult ones.
What about for trickier block diagrams, where the solution isn't that obvious? Where does one start?