I'm sure it's most likely frowned upon but on the smaller scale apartment buildings, during due diligence has anyone ever tried speaking with tenants to uncover any existing conditions or deferred maintenance problems they may be facing? 

Unfortunately for anyone looking for these investment groups, it is still a "who you know" game, or at least becomes a lot harder and entails more networking, typically higher buy-ins, and/or lots of research to uncover these groups.

Get a property inspection: As you mentioned, you will need to hire your own inspection company to inspect the property and uncover any potential issues that may affect its value or safety.4.

Purchasing from overseas, I made my offer based on the advertised info and, believe it or not, did not uncover that 2 of the units were just 1b/ 1ba until after due diligence. 

Sometimes talking to locals or joining real estate investment groups can uncover hidden gems.

The best way to explaining this is for you to download an IRR calculator spreadsheet or build your own simple one and play around with one.For what its worth most deals I deem meeting minimal IRR standards is 13-15% but you have to dig a little deeper to uncover the real placements of cashflows and capitalization events... and then dig even deeper to verify the assumptions such as occupancy, rent increases per year, and what reversion cap rate was used.Again I don't look for IRR cause its manipulated a lot instead I look at total return on a 5 year basis.

They will have their quirks and you might uncover things as you get into it so be conservative

A mix of determination, perseverance, and a bit of luck can uncover hidden opportunities in unexpected places.

I will share my "Most Expensive Lesson" in the comments.To kick things off, here are ten examples of expensive lessons or mistakes in real estate investing:Underestimated Repairs: The classic pitfall where the cost of repairs and renovations far exceeds initial estimates, impacting the overall budget and profitability.Tax Liens: Failing to account for or being unaware of existing tax liens on a property can result in unexpected financial burdens.Contractor Liens: Not settling payments or disputes with contractors can lead to liens against your property, complicating sales or refinancing.HOA Fines: Overlooking or violating Homeowners Association (HOA) rules can lead to significant fines and headaches.Bad Loan Products: Opting for loan products without fully understanding their terms can lead to unfavorable financial conditions, such as higher interest rates or unfavorable repayment terms.Ignoring Zoning Laws: Investing in a property without a clear understanding of local zoning laws may restrict its use, affecting your investment strategy.Overpaying for a Property: Lack of research or getting caught in a bidding war can result in paying much more than the property's worth.Neglecting Due Diligence: Skipping thorough inspections and background checks can uncover unpleasant surprises after the purchase is finalized.Poor Tenant Screening: Failing to properly screen tenants can lead to unpaid rent, property damage, and costly evictions.Underestimating Market Risk: Not considering market fluctuations can lead to investments that don't pay off as expected, especially in volatile or declining markets.We've all been there in one way or another, facing setbacks that seemed daunting at the time.

Uncover valuable tips and strategies for maximizing the value of your property through carefully planned improvements.