One of the most important aspects while learning how to make a good Rangoli design is to understand how to hold, release and use Rangoli powder. Check this short 1 minute video and learn the basic technique.
While you can use Rangoli kits so that you can make great Rangoli designs easily, it does not hurt to know the fundamentals of Rangoli making, the way it has been done for centuries!
Check this video and start on your Rangoli making journey.