Also known asmirrordarpan
In older vastu practice mirrors were the main tool of dosh nivaran: a mirror can make a cut area look larger or an oversized extension look smaller.
At the cut or extended portion of the plot or room
For a North-East cut, for example with an exalted Ketu whose diagonal points to the North-East, a kalash is installed in the North-East with mirrors fixed all around it.
North-East
In a dressing room or bathroom mirrors should go on the North or East walls. If a wash basin is already in the South and its mirror must be there, fix a mirror of the same size on the North wall to balance it.
North wall opposite the South mirror
As taught in class, a convex mirror makes a small space look bigger and extends it, while a concave mirror makes a big space look smaller; so a convex mirror treats a cut and a concave mirror treats an extension. A plain mirror can also extend a cut.
North or East wall of the cut part; inside of the wall to extend, outer side to reduce
A mirror placed for income (aay) increases income: people keep a small mirror in the wallet or fix mirrors inside the galla or tijori so the money appears multiplied.
Inside the cash box, galla or tijori; in the wallet or pocket
Use one whole mirror on the North wall. Do not join small pieces of mirror for a design; that turns mangal (auspicious) into amangal.
Yes, whether the mirror is in the house, the temple or anywhere else.
No. The darpan is considered auspicious and is used even in pooja; do not replace it with plastic films.
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.
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.
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.
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.
A dressing room has four walls, so fix the mirror on its North or East wall. If the wash basin is already in the South and its mirror must be there, fix a mirror of the same size on the North wall; the pit made in the South is matched by one opposite and the effect evens out.
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.