I’ve got a background in electronics.

Tear downs on YouTube are invaluable.

Unless I’m explicitly buying something to take it apart I avoid anything mains powered.

You can replace the plugs and cables with compliant ones. And you can fix the lack of proper earthing. But who knows what other problems there are.

For household items, I do tend to stick to known brands and would probably avoid places like Amazon.

In the U.K. we have various high street shops such as John Lewis that do have reputations to maintain.

I would also avoid anything that has large lithium batteries.

Some basic heuristics can go a long way. Does a £2 USB-C charger that claims to do 200W make sense? Probably not…