In my case it was not as simple as wake up and do it.  

My mentor helped ALOT with advice, helping me stage she used to be a fashion designer in NYC (where I'm originally from) and is now both an Airbnb arbitrage investor and a real estate agent where she personally stages all her properties that she sells or Airbnbs.

At its core property management is simple though.

Anything smaller may not attract larger investors or offer the economies of scale needed for profitability.Design Style: BTR developments often consist of attached townhomes, usually with features like garages and a more upscale design to appeal to renters looking for something between an apartment and a single-family home.Location Factors: The success of your development depends heavily on location.

*Development plans for expanded Hoffman Town Center*Although specific tenants have not been named yet due to the development being in the earlier design and planning stages, the vision as described by Hoffman Co. is a commercial and residential mixed-use development including a new public school, storage center, city agency training, a farmer's market, festival space, beer garden, and "other similar uses approved by the city".Sources:Developer laying groundwork to go bigger in Alexandria’s Eisenhower corridorAlexandria considering big plans for properties next to Eisenhower Avenue Metro stationPotomac Yards Alexandria: The 2$ Billion Sports Arena is not the Biggest Development in the Pipeline for Potomac YardsThe Sports Arena was a recent idea that was part of a bigger plan approved in 2017, that called for a massive shopping center at Potomac Yards and the surrounding area to be redeveloped into 1.9 million square feet of office space, 1.1 million square feet of residential space, 900,000 square feet of retail, 300 room hotel, and 9.3 acres of open space by JPG Smith.

That way you can work backwards on the land price AND your holding costs while you're designing, permitting, and building the home. 2.

Quote from @Gary Aragon: Quote from @Rick Albert: Our electricity is already separate and we designed our ADU to be all electric so no gas. 

I am the only real estate investor with my bookkeeper and at first she thought this was a little overboard but once she started setting rules in Quickbooks to simplify her work she quickly realized how simple this method makes things.

Can I still do simple 4 box calculation? 

I don’t have an STR myself but have helped a friend set up and manage a couple last year and it’s not as simple as it used to be.