Acharya Indu Prakash talks about the places you can put a mirror at to fix Vastu defects. If there is a bathroom or toilet built in the basement or southwest corner of your house, then you should put a square-shaped mirror on the wall of the east direction. This will remove the Vastu defect of your house soon.
If any part of your house is of unusual shape or dark, then you can balance the energy by placing a mirror, in that part. Apart from this, if there is an electric pole, tall building or unwanted trees outside your house, you can diagnose them by placing a pakwa mirror on the main door of the house. The pakwa mirror is in an octagonal wooden frame on which workmanship made from the thread is also found. This frame is mostly red, green, yellow and gold.