@AP Horvath do you see yourself spending time involved with all of the details of RE investing ( finding deals, doing walkthroughs, negotiating with sellers, getting estimates, working with contractors, putting out adds and screening for tenants, dealing with property/ tenant issues, applying for loans, booking keeping, etc) ?
If yes, the margin of safety rule I use is - A deal that you can refinance and get 100% of what you put in (purchase + repair costs) and still cash flow every month likely has a strong margin of safety.
Other advice is take what the market gives you. For example I’m find it difficult to find properties in decent areas for a price that meets the margin of safety rule above. However I’ve been finding that even though these deals won’t cash flow they can work as flips.
If your answer is no to the first questions above, then maybe consider checking out syndications, turn key rentals, private lending to experienced investors, REITs, etc.