I’ve read about strategies like house hacking but am not too enthusiastic about what it would take (also not very feasible given the current cash I have), also the ‘BRRR’ method, though I wonder if it might be too ambitious for my first property.

With these methods, you would be able to reach a large number of sellers without necessarily spending too much per contact, as compared to direct mail.

Other methods? 

Quote from @David Ramirez: Call remodeled comps in the area that has been bought and sold within a year Especially for this method, you can paste the addresses in propwire and look in the chain of title to see the last owner before it was sold after being fixed up.

Cold calling is only one marketing method.  

But hey its money whether its a living is another matter For the future I am switching to the buy it off the market and put it on the MLS with a realtor method.

I would consider doing vanilla long-term rentals, but I think I want to do the BRRRR method, as scaling will be a challenge for me without it, I feel.

You listed two but in broader terms financing (assumable, owner financed, sub to, fha, new 95% OO LTV that in most ways is superior to FHA, dscr, F/f conventional, NACA, VA, etc), value adds (development including ADU, upzoning, traditional rehab, sophisticated value adds that leverage localized rules, coop/tic, etc),  property types (residential, commercial residential, land, storage, MHP, industrial, office, camping, hotel/motel, etc), passive/active investment methods (GP, LP, REIT, nnn, self managed, pm, flipping, mineral right, lumber rights, etc), residential rent models (LTR, STR, MTR, rent by room, student housing, arbitrage, etc).  

The forum you posted in is about the BRRRR method. 

Are there any practical methods for implementing usage-based billing without submetering?