The interior in any shop should be done according to the type of the business and with reference to the Vastu Principles.
Some points to check are as follow:
The centre of the shop should kept empty
The owner or the cashier should sit in the South West corner and should face East or North.
The North/ East should have windows or open areas.
The finished products should be kept in the North west Corner. If have multiple racks of the products then it can be kept along the South and South West walls also
Stairs can be made in South West, South or South East directions
All other objects like paintings, posters, colors used in the shop and any other article should be vastu compliant
