Your best bet is fixers - houses with obvious major issues that everyone is scared of but you know you can fix reasonably cheaply. This can mean buying a $500k house with major foundation damage for $100k because everyone is scared - but you know a whole foundation replacement will only run you $200k.
And it is not like you can find such disasters easily, nor that you can easily be able to make them into fixers, without years of previous experience.
The whole approach, "everyone is scared but you know ..." is based on the assumption that you know more than anyone else (possibly including many people dealing with this kind of stuff for decades), I doubt that anyone can learn what is needed in this field overnight, by reading a book, and should it be possible, everyone woild do it, not just you.
Anything that "anyone can do" is going to explode at some point.
keep assets instead of cash and you'll be a genius
The "somewhat specialized" knowledge can be explicited as four main things:
1) years (and I mean years) of experience in the field (to be able to quickly assess the non-evident potentialities of a building)
2) knowing a few good, tested, reliable technicians such as architects/engineers (to be able to get a valid project leveraging on these potentialities)
3) knowing (more than) a few good tested, reliable, capable firms (masons/carpenters/plumbers/electricians/painters/etc.) to actually execute the restoration
4) time to be dedicated to managing the project
If you think that - even if you actually happen to find a "gem" - that you can make money hiring people you find on the internet or on the yellow pages, or that the people involved will manage to do a good work at a fair price by themselves, you won't go very far.
The problem I see is that you need to find the fixer gem, but location matters. Certainly, you can buy a fixer in the middle of Ohio, but who wants to live there? There is just too much surrounding inventory with low desirability.
The thing that works in my eyes is to buy in areas that are extremely desirable, even pay a bit more for it, but very low inventory. That's where the insane appreciation comes in. Popular beach towns are a good example because they are land locked and can also be turned into short term rental properties relatively easy, which increases their perceived value.
It isn't easy to find such places and often requires paying in cash, but it is possible.
Millions of people. It's the seventh largest state in the USA, is home to three major cities and many large multinational companies.
The millions of people who live there, already live there. That doesn't increase demand. It is a large state, so there is plenty of space to build. Density is centered around three locations and the largeness of the state means that people can expand out to the suburbs.
What you want is somewhere with a high density, inability to add more property and desirable for vacations (like a beach with views). San Francisco was kind of a good example of this for a very long time, until it wasn't. There are other cities on coastlines that fit this model though.
Buy a condo that has dual use (STR), refurb it, flip it.
In the back of my mind, I think of flipping houses as something to do if I ever get laid off from my tech job. I look at places coming up for sale on Zillow that were obvious flips and they all look like the parts all came straight out of Ikea / HomeDepot (and usually the most ugly stuff to choose from).