Just a non-obvious thing I learned doing this for a while: try commercial real estate. I see two big advantages, that have played out in practice for me but also structurally. The tenants are companies, who tend to stay much longer, invest more in leasehold improvements and be less demanding (unless something is critical to their business which you are probably aware of ahead of time). The other is that unlike in personal real estate, you can sometimes buy it with a vendor take back mortgage (ie. the seller mortgages it to you). This is risky if you are ever likely to miss a payment, but an excellent way to get more leverage than the bank might give you in a way appealing to both sides.
Excellent points. But how do you "add value" with NNN investments? I've always seen them more as like a fixed income instrument.