I'm trying to learn right now. I'm probably doing this backwards but:

I'm starting by soldering together kits for modular synthesis. That's teaching me all of the technical skills and ensuring I have the right tools. Some friends to help correct my shitty habits have given me the right skills and equipment to build.

Then I know how to assemble things, so now I'm trying to build my own very simple circuits. Once I can breadboard them, my friend can help show me the ropes to get PCBs printed and then I can manufacture my own things.

Finally, the troubleshooting exposes you to a bit as you have to understand what's going on.

Learning and watching on the side take the basic exposure and distill knowledge from that.