Hopefully you know some local fellow investors, but if not, certainly developing this local network is important and would put an emphasis on that as well.   

Quote from @Arvand Sabetian: I think most others have already provided sound advice.I wanted to emphasis having a conversation with your tenants about the septic tank, not just a clause in the lease that you assume they'll read and understand.Many people are unaware of what they can be doing that causes issues to septic tanks (e.g., flushing the wrong items).Also, make sure you do a walkthrough yourself prior to filling the unit.

Even if you did entire build yourself, I think you are looking at 2.5 times your estimate and a lot of work and time.I suggest you go to some meet ups with an emphasis on understanding the value added by ADUs.  

By placing more emphasis on the condition of residents’ dwellings, the new inspection model aligns more closely with stakeholder expectations regarding housing quality.

From page 730 (emphasis mine): "All non-business tax deductions and exemptions that were temporarily suspended by the 2017 tax bill should be permanently repealed, including the bicyclecommuting expense exclusion, non-military moving expense deductions, and the miscellaneous itemized deductions.23 The individual state and local tax deduction, which was temporarily capped at $10,000, should be fully repealed.

You should be placing far greater emphasis on the  fundamentals of the neighborhoods in which you invest.

These days, I’m all in on Google Ads.One last thing is to start working with PROFESSIONAL wholesalers (emphasis on PROFESSIONAL).

I get the emphasis on tax savings, but I'd be wary of investing for the sake of it.

But if you're disciplined in money management, which is what they don't really put an emphasis on, then it might just work.  

The problem most encounter is placing too great of an emphasis on the return of capital at the end of the renovation process.