They get pictures and a line-item accounting of the deductions from the security deposit.  

If you look at 8 houses, and you are reviewing all at the end of the day, you can tell where one ends and the next begins,  We also make sure not to take too many pictures. 8 max of only the high ticket items, roof, windows, kitchen, electric panel, kitchen, baths, furnace, ac, front and back, andything unusual,  i dont want a picture with a hole in drywall that will cost 25.00 to fix, no pictures of carpet of paint, or things we will replace in every house.... always a couple photos for perspective. 

The construction work is mostly cosmetic with the biggest items being fixing a deck and kitchen rehab work. 

Salesmen at my local gun store said they have had a hard time keeping guns in stock after all of the Ferguson violence.

Immerse yourself with the different references materials Brandon itemized  above.

If you walked out of a grocery store without paying the manager would call the cops and label them a thief. 

Conventional financing guidelines are vague when an appraiser has to call the various items you mention. 

The store my daughter worked at ended up being taken away from the franchisee. 

In fact, that is a pretty contentious item in this community.  

You cant report some income/expense on schedule E and carve out the interest expense from the line of credit and call it an investment activity and an itemized deduction on schedule A.