Things that you may want to avoid

One of the most common fengshui problems, the block (background) is located in between the two blocks (foreground).
Tian zhan Sha 天斩煞， looks like a chop from the sky.

Unit that can see gap in between two blocks. Usually fengshui is discounted.
Another common fengshui problem, unit that is too close to street lamp.
Looking at another angle.