Vegetation can make an excellent screen against undesired views. A food hedge makes a great fence to screen over an ugly warehouse, bright street, vacant lot, or pesky neighbor.

You can also use some kind of structure, of course. Sometimes that will involve more rules, and some people just prefer using plants.

Ideally this should be part of a complete sector analysis, which also considers things like sun and wind direction.

https://www.greenpathherbschool.com/greenpathblog/permacultu... (scroll down to "Sector Analysis")

https://smalldesignstudio.wordpress.com/a-permaculture-proje... (scroll down to "sector map")