Just to add some: There's a lot of specialization in EE like any other field and you can't really dive into everything. I find power electronics to be more of a

Just to add some: There's a lot of specialization in EE like any other field and you can't really dive into everything. I find power electronics to be more of a black art than RF or high speed digital so I try to never design my own. I've seen people spend years working on a single design for a solar inverter making dozens if not hundreds of iterations, testing with all types of switching circuits and chips, comparing the behavior of one vendor's capacitor to another, understanding different transistor behavior, and so on. Thankfully, nowadays you can go to TI and use their automated schematic generator for your power supplies. They have many reference designs and tons of documentation on PCB layout in a variety of situations. Debugging them, however, is a whole different story. If you can afford it just buy a module and never think of it again. Polyfuses are a godsend, especially if you're designing a high current PCB like a motor controller. It really doesn't take much to melt a 1.5 oz 10 mil trace. How expensive trial and error is depends on your experience. When I'm done with using a board or have some old electronics to throw away, whether I bricked it or its obsolete, I always throw it in a pile. When I have time I just go through and desolder each nontrivial part because it helps build an intuition for how each type of solder will respond to heat and flux, how wick looks as it absorbs solder and how to move it to get all the solder without overheating the chip, and so on. You need to develop that muscle memory like a surgeon would because once you're good enough you can do crazy things like snake a tiny wire under a BGA chip under an xray to fix flaws in the design or reflow. In more expensive designs I'll regularly take small gauge wire and solder it all over to fix the design as well as cut traces or lift copper layers after stripping the FR4. Hand assembling electronics is largely more craft than engineering.