Many years ago I did write something while we were waiting to see what would go for the 3ds that detailed some things worth knowing here
https://gbatemp.net/threads/some-hacking-concepts-and-links.287721/
It is pretty much the same today.
Similarly most times the people doing the hacking, or some portion of it, will have a presentation at the various hacker/tech conferences detailing what they found and how they approached it.
Wii
Xbox 360 (though notably the comment about "nothing interesting there" was wrong and eventually led to the RGH family of hacks)
Original xbox
There is also a mistakes made PDF/website flanking this that is good to read, as is Bunnie's doc
https://bunniefoo.com/nostarch/HackingTheXbox_Free.pdf
3ds
PS3
https://media.ccc.de/v/27c3-4087-en-console_hacking_2010
Beyond that most of said same conferences also detail the fun and games people have with different techniques (the rise of ROP was a fun one for a few years, prior to that fun with FPGAs, when it turned out the Wii controller spoke a common comms protocol...) so well worth watching there.
Going the other way many of said conferences will feature a breakdown of older consoles (usually titled the ultimate ? talk where ? is a console, or in one case an apollo guidance computer).
https://media.ccc.de/search/?q=ultimate will get you some.
The increased security of modern devices changes things somewhat, though it is also somewhat offset by you being able to ship things to your house that 15 years ago my million dollar lab would have had to pause before considering.
