that playlist actually looks promising, will have a look later.

I'd add: Learn to recognize dangers first. From the top of my head:

* big caps that can contain high voltages even when a device is powered off, in TVs or microwaves.

* Know where a fire extinguisher etc is, keep them near the workbench.

* Keep the workbench clean, tidy and well-vented.

* Don't panic when mistakes are made. Slow down instead of doing a quick-fix.

* I like a big red button to power down everything instantly. Can be just a switch on a plug box.

Definitely

Risks to consider in general are (also of the top of my head don't take as exhaustive):

* Electrocution

* Burning yourself

* Setting stuff on fire

* Fumes, both from soldering and overheating/burning plastic

There's a kind of balance between habits and awareness. Rely too much on awareness and you will miss some safety issue during a complicated repair. You need good habits, but rely too much on them and you won't notice when you finally make a mistake.

Those apply during repair processes. It's also possible to render a device unsafe to use, for example by damaging a li-ion battery or by a 'bodge' repair that circumvents a safety feature.

A tip on how to reinforce good safety habits taught to me by my shop class teacher is to refer to any dangerous tool you are using by the kind of injury it is likely to inflict. The lathe is the deglover, the angle grinder is the eye splinter injector, the welder is the retina tanning machine, the soldering station is the IQ diminisher, etc. This helps to put you in the mind of "I need the eye splinter injector for this task, how shall I go about avoiding getting splinters injected into my eyeballs?" instead of getting complacent.

> "I need the eye splinter injector for this task, how shall I go about avoiding getting splinters injected into my eyeballs?"

Reminds me of the comments I read on a video of somebody doing something unsafe - "safety squint".

That's certainly a good way to put you in the right mindset - although many of them can injure you in more than one way.

Also let someone know where you are and by what time you plan to have completed the job, could save your life

If you're often working with mains-voltage things, you can use:

* an isolation transformer - meaning you must now touch both conductors to get shocked instead of just the live one

* a foot switch to control the power supply - serves as a "dead man's switch" to cut power in case of an accident

(these are not mutually-exclusive, you can combine them)

I loved Rossman's explanation of the transistor. Transistor is just a controllable resistor. So simple. No one told me this. I could have saved years!

I'll just say, "thank you".