We had reasonably good success with investment property. Bought in 2013 and it provided solid income over ~7 years, and recently sold for quite a bit more than we paid. No regrets, but in hindsight we would have done better just staying in equities. Would I do it again? Maybe, but only if I found the exact right location/property. However, I will never landlord in California again due to the regulatory environment, though that's a topic for a different thread.
Rentals are a business and there's nothing particularly special about real estate. Like all businesses there are good ones and bad ones. Success is largely determined at the point of purchase. If you overpay for a property it's nearly impossible to recover unless you happen to get lucky and buy in a place where rents rapidly increase. And capital appreciation is very unlikely to bail you out in a LCOL area. However, get a good deal and it's likely to work out well.
So treat it like a business and do everything by the numbers. Evaluate potential properties on a spreadsheet comparing metrics like cap rate, IRR, ROE, etc. This should be cross compared to things like the risk free rate, equities, and bonds -- no point getting into landlording if it doesn't compare favorably with passive investments.
You should know, off the top of your head, what different types of units rent for in specific neighborhoods. It may take months or even years to find something that works, or you may never find anything where you are looking (some areas are simply terrible rental markets). And that's fine, don't worry about walking away, which is way better than having an albatross hanging around your neck for the next 10 years.
If you do find a property that pencils out, keep running it like a business. Very very carefully screen tenants. I cannot stress this enough. One bad tenant can wreck everything. Maintain the property and keep it in good basic working condition: replace appliances and do repairs as needed, but resist the urge to do anything high end. Go for safe and clean and functional, but basic. Keep rents in line with market rents for the area, not the absolute highest, but also not too low. Usually this means small annual rent increases, but could also mean rent decreases in down years. You want to avoid a situation where, over many years, rent gets very far below market.
I'd be interested to hear more about your rationale for why you think this would be a good investment option for you.