What is the right way to wear a Sari?

There are more than 80 recorded ways to wear a sari.

The most common style is for the sari to be wrapped around the waist, with the loose end of the drape to be worn over the shoulder, baring the midriff.  However, the sari can be draped in several different styles, though some styles do require a sari of a particular length or form.

The word sari is derived from Sanskrit which means 'strip of cloth' The term for female bodice, the choli is derived from another ruling clan from ancient Tamil Nadu, the Cholas.  The one piece sari is modern invention combining the bodice and the skirt. 

The nivi is today's most popular sari style.  The nivi drape starts with one end of the sari tucked into the waistband of the petticoat, usually a plain skirt. The cloth is wrapped around the lower body once, then hand-gathered into even pleats below the navel. The pleats are tucked into the waistband of the petticoat. (fabric is approx. 4' wide and 5-7 feet long)

After one more turn around the waist, the loose end is draped over the shoulder.  The loose end is called the pallu, pallav, seragu, or paita depending on the language.  It is draped diagonally in front of the torso. It is worn across the right hip to over the left shoulder, partly baring the midriff.   The navel can be revealed or concealed by the wearer by adjusting the pallu, depending on the social setting. The long end of the pallu hanging from the back of the shoulder is often intricately decorated. The pallu may be hanging freely, tucked in at the waist, used to cover the head, or used to cover the neck, by draping it across the right shoulder as well. Some nivi styles are worn with the pallu draped from the back towards the front, coming from the back over the right shoulder with one corner tucked by the left hip, covering the torso/waist.

Because of the harsh extremes in temperature on the Indian Subcontinent, the sari fills a practical role as well as a decorative one. It is not only warming in winter and cooling in summer, but its loose-fitting tailoring is preferred by women who must be free to move as their duties require. For this reason, it is the costume of choice of air hostesses on Air India.  This led to a professional style of draping a sari which is referred to Air-Hostess style sari. An air hostess style sari is tied in just the same way as a normal sari except that the pleats are held together quite nicely with the help of pins. A bordered sari will be just perfect for an Air-Hostess style drape where the pallu is heavily pleated and pinned on the shoulder. Even the vertical pleats that are tucked at the navel are severely pleated and pressed. Same goes for the pallu pleats that are pinned at the shoulder. To get the perfect ‘Air-hostess’ a complimentary U-shaped blouse that covers the upper body completely is worn which gives a very elegant and formal look. Mastering the ‘Air-hostess’ style drape helps to create the desired impact in a formal setting like an interview or a conference.

Saris are worn as uniforms by the female hotel staff of many five star luxury hotels in India as symbol of culture. Recently in a makeover design, Taj Hotels Resorts and Palaces, decided the welcoming staff at the group's Luxury Hotels would be draped in the rich colours and designs of the Banarari six yards. The new saris were unveiled at the Taj property in Mumbai. It will be subsequently replicated at all 10 Luxury Hotels of the group across the country for duty managers and front office staff. 
Source: Wikipedia         Click on this:  How to wear a Sari