I stay away from anything that won’t cash flow well, that’s more than 45 minutes from home, and is in an area that I wouldn’t personally live in if I had to.
In Columbus OH, I invest in multi-family and look for properties that cash flows well. I tend to stay away from single-family because it can more work.
I avoid Flat or asphalt shingle roofs, houses with no garages, yards with lawn, split levels (a landing at the main entrance and then you have to go up or down stairs.), houses with less than 3 bedrooms and 2 baths so people stay longer, and multi-Family. (To avoid tenant vs tenant or common area conflict.)
I avoid large old houses in once-prosperous, now C-class areas that were converted at some point into makeshift duplexes and triplexes. The electricity, plumbing, and/or heating in these places were invariably rigged by a drunk Mickey Mouse, whatever additions were built are of incredibly shoddy workmanship, and the last municipal inspector in there was obviously bribed to look the other way. In my town, they don't call me Jimmy Krapshacks for nothing, but there's a certain level of krap even I won't stoop to (or squat for).
I stay away from anything that won’t cash flow well, that’s more than 45 minutes from home, and is in an area that I wouldn’t personally live in if I had to.