There are many instances scribbled in the past which tell us how our karma (our deed) can change the kismat (fate). The legend associated with the festival of Dhanteras is one such instance when an individual through his persistent karma and belief changed the world around him.
As the legend goes, the horoscope of King Himas sixteen year old son read that he would die on the fourth day of his marriage by a snake bite. On that particular fourth day of his marriage, his young wife did not allow him to sleep. She laid all the ornaments and lots of gold and silver coins in a big heap at the entrance of her husband's boudoir and lighted innumerable lamps all over the place. And she went on telling stories and singing songs. When Yama, the god of Death arrived there in the guise of a Serpent his eyes got blinded by that dazzle of those brilliant lights and he could not enter the Prince's chamber. So he climbed on top of the heap of the ornaments and coins and sat there whole night listening to the melodious songs. In the morning he quietly went away as the time allotted for his death had passed. Thus the intelligence of the young wife saved her husband from the clutches of death. Since then this day of Dhanteras came to be known as the day of "Yamadeepdaan" and lamps are kept burning throughout the night in reverential adoration to Yam, the god of Death.
So Dhanteras is celebrated as a reminder for those who have a certain fear about some ills in their horoscope. Here the importance of karma is kept well ahead of kismat and it is reminded again and again that the kismat can be mended provided the ills as depicted in the horoscope are known and due remedial measures are resorted to.
The festivity associated with Deepawali starts on the thirteenth day of the waning moon of the Hindu month of Kartik which is Dhanteras and ends after five days with Bhai-Dhooj.
Here is the methodology adopted for celebrating the worshiping on the day of Dhanteras and by ritually following the ills if there in the horoscope can be kept at bay but it has to kept in mind that these are generalized and not particular.
To mark the auspicious day, houses and business premises are renovated and decorated. Entrances are made colorful with lovely traditional motifs of Rangoli designs to welcome the Goddess of Wealth and Prosperity. To indicate her long-awaited arrival, small footprints are drawn with rice flour and vermilion powder all over the houses. Lamps are kept burning all through the nights. Dhanteras is celebrated with passion and enthusiasm. "Lakshmi-Puja" is performed in the evenings when tiny Diyas of clay are lighted to drive away the shadows of evil spirits. Bhajans or devotional songs- in praise of Goddess Laxmi are sung and "Naivedya" of traditional sweets is offered to the Goddess.