I had a tenant stay for 2 years in my apartment and they did more damage than when I lived there for 8 years (broke washroom door handle lock, toilet paper roll, bent blinds, tons of scuff marks on walls, granite counter top is somehow scratched, etc.)2) They also won't negotiate rent increases well since they only take a %, an increase doesn't usually mean much to them at all.

(Granite counters, tile showers, etc)

If the counter tops are Formica instead of granite, put in new Formica, it's the "new" part that is a sufficient upgrade. 

., super fancy granite counter tops) but "solid" (mid-level in price/quality) that give the ADU a modern look and feel and a foundation of materials that would last a fairly long time without being refurbished.She is getting quotes with a fairly wide range, from $140K all the way up to $190K.Thanks in advance!

Lowes has a nice in stock countertop that looks like granite it's white, black and gray.

House some larger storage tanks for waste that you could have pumped.3) Find a business (excavator, plumbing, granite supplier) and trade on-site "night security" in exchange for a spot to park and use of the bathroom/shower inside the facility.

I just think you did a cheap renovation and it shows, I mean you painted over wood panel, no granite in the kitchen, old cabinets w no knobs, you didn't open up the space between the living room and the dining room, you didn't tile the bathroom shower, who knows what the vanity looks like and its a 2bd/1 bth with a house in a not great area. 

@Frank SzymanskiFor the rental in fl, here is what I would do: Remove uppers over the U, add nice lightsFloating LVL floorsMove cook top over to the left, nice hoodExtend an L with the counter top to provide seating on the other side, round the edge of the counter topBuy / replace appliances, may be counter depth fridge with ice and water on the doorUse quartz / granit for counter top, or butcher blockAdd nice lights, new big sink & nice moen faucetI'd lightly hand sand cabinets and spray new coat of polyGood luck

Cheap labor often requires more oversight.A tenant turnover that has taken good care of the unit is nearly $1k (patch pin holes and touch up paint, steam clean carpet, seal grout/granite, toilet flaps, clean drains, misc).  

I also did stainless in that one, and slab granite instead of granite tile.