You've already had some on here although they were pretty subtle.  

Make it subtle.

Look for the subtle signs that your property will undergo gentrification during your tenure as landlord.

Its not subtle insults.

You need to drive thru blocks and blocks of areas surrounding a house you like to get the local flavor.

This study is not comprehensive and you may need to be aware of the subtle racism in promoting sweeping generalizations about entire races based on limited studies like this. 

You should be installing the same kitchen over and over again, with subtle differences, 2 -Floors = Go to your local supplier, and price materials. 

For me it is an experience.It's just like some people eat stuff that tastes like cardboard for food just to keep themselves going and others really can tell when they are eating something amazing with all the colors, textures, layers of flavors with the food.

Then with white cabinets many designers are going for white subway tile for the backsplash or a subtle color of glass subway tile, that's always nice.

, or have mental health difficulties, or experienced/are experiencing trauma in their lives, or experience subtle or not-so-subtle racial or sexual discrimination when they look for housing, or are going through a devastating illness, etc. etc. etc.