For a cut, should the mirror be fixed on the inside or the outside of the wall?
Fix it on the inside of the wall of the part you want to extend; seen from inside, that portion looks bigger and is extended. Fixing it on the outer side makes that part look smaller, so the outer side is used only when a part must be reduced.
Related questions
What should be done when Ketu is exalted in the 2nd house and the house has a North-East cut?
Rahu-Ketu belong to the South-West, and the diagonal from there is the North-East. Put a mirror at the cut, or install a kalash in the North-East and fix mirrors all around the kalash.
What size of mirror is needed to extend a cut?
A plain mirror shows about three times its size, as a 2 ft mirror shows a 6 ft person. For a 10 to 12 ft area with a 12 ft cut, use at least a 2.5 to 3 ft mirror; even a 1 ft mirror works to some extent, but the result depends on the area and the mirror quality. Use a convex mirror to enlarge a cut and a concave mirror to reduce an extension.
With the East-North-East missing and the North-East cut because of a staircase, where should a convex mirror be placed?
Put the mirror for the zone that is missing. Fixed so that it works from inside towards outside, it extends and enlarges that missing space.
Can a mirror be fitted on a wardrobe in the S, SSW, SW, WSW or West?
No. Wardrobe mirrors also belong on the North or East wall. Some say the North-West is also allowed because the mirror represents the water element and the Moon.
Can mirror films be used instead of mirrors?
No. The darpan is considered auspicious and is used even in pooja; do not replace it with plastic films.
For depth at an entrance in the North, is one big mirror better, or will design pieces do?
Use one whole mirror on the North wall. Do not join small pieces of mirror for a design; that turns mangal (auspicious) into amangal.