I couldn’t vote because it requires 3 options. The only one there that applies to me is written tutorials.
As others have said, you could have included trial and error. But a glaring omission is learning by reading datasheets and experimenting. You seem to be fundamentally limiting yourself and everyone else to the diy equivalent of buying and assembling lego kits.
I learn by deciding what I want to accomplish, figuring out what components are necessary, learning you use those components, and then combining them together.