The only way to discover your strengths is through feedback analysis. Whenever you make a key decision or take a key action, write down what you expect will happen. Nine or 12 months later, compare the actual results with your expectations.
"Kant described a mechanism as a functional unity, in which the parts exist for one another in the performance of a particular function.
An organism, on the other hand, is a functional and structural unity in which the parts exist for and by means of one another in the expression of a particular nature.
This means that the parts of an organism – leaves, roots, flowers, limbs, eyes, heart, brain – are not made independently and then assembled, as in a machine, but arise as a result of interactions within the developing organism."
— Brian Goodwin, How the Leopard Changed His Spots
In my opinion, what makes a designer competent is precisely their ability to credibly justify their conclusions. If you can’t do this as a designer—no matter how successful your results are—then neither I nor anybody else can tell if you aren’t just picking things at random.
What I am proposing, then, is no less than to make a designer’s entire line of reasoning a matter of permanent record. On the surface is the familiar set of prescriptions, components, examples and tutorials, like you would expect out of any such artifact. Attached to every element, though, is a little button that says You click it, and it tells you. The proximate explanation will probably not be very satisfying, so you click on the next until you get to the end, at which point you are either satisfied with the explanation, or you aren’t.