The best oil to light up lamp before god is cow ghee. Next comes ordinary oil. “Mahua flower oil” or “ippa oil” might be extraordinary. The benefits of lighting up the lamp with ghee oil are ultimate. We get ‘ashta aishwarya’ and ‘ashta bhoga’ (great wealth and health)
If we light the lamp with ‘amudham oil’ (in Telugu), castor oil we get fruitful marriage life, and would be able to maintain good relations between wife and husband.
NOTE: It is said we should never light the lamp with ground nut oil before god.
When it comes to goddess Maha Lakshmi, it is prescribed to light up the lamp with cow ghee, and when it comes to Lord Ganesha, it is recommended to light up the lamp with til oil (nuvvula nuna in Telugu)
Many people say it bad sign to start work on amavasya (no moon day). But many of them don’t know that the battle of Mahabharatha started on amavasya. Pandavas won the battle on kauravas. It was the date on which dharma won.
In many states in India, people wait for no moon day to start their auspicious works. On a contrary, it is also believed that amavasya is the best time to learn and perform black magic work. On another occasion Indians celebrate Diwali festival on naraka chaturthi.