There are two primary ways to make a Rangoli:- dry and wet, referring to the materials used to create the outline and (if desired) fill that outline with colour.
Using a white material like chalk, sand, paint or flour, the artist marks a centre-point on the ground and cardinal points around it, usually in a square, hexagon or circle depending on region and personal preference.
Ramifying that initially-simple pattern creates what is often an intricate and beautiful design. Motifs from nature (leaves, petals, feathers) and geometric patterns are common.
Less common but by no means rare are representational forms (like a peacock, icon or landscape). “Readymade Rangoli” patterns, often as stencils or stickers, are becoming common, making it easier to create detailed or precise designs.
Once the outline is complete, the artist may choose to illuminate it with colour, again using either wet or dry ingredients like paints, coloured rice-water, gypsum powder, coloured sand or dry pigments.
The artist might also choose unprocessed materials like seeds, grains, spices, leaves or flower petals to achieve lifelike hues. Modern materials like crayons, dyes or dyed fabrics, acrylic paints and artificial colouring agents are also becoming common, allowing for brilliant and vibrant colour choices.
A newer but less artificial method involves using cement coloured with marble powder. This rather precise method requires training, but beautiful portraits can be drawn in this medium.
Shape, design and material can be influenced by regional traditions. A square grid is common in North India as is a hexagonal grid in South India; Onam Rangolis are typically circular.
In North India, the colour is most often based on gypsum (chirodi), in South India on rice flour and Onam Rangolis are typically flower based. The rapid and widespread migration and mixing of people within India can be seen by the way these styles are now freely adopted and mixed across the country. It is also becoming common to see experimentation like sawdust-based floating Rangolis, freeform designs, and exotic materials.
It’s particularly notable that the Tamil version of the Rangoli, the Kolam, prizes symmetry, complexity, precision, and intricacy rather than the flamboyance of Rangolis found in North India. Many people find it enjoyable to try and figure out how such intricate designs are drawn with a grid, and hence, it allows the mind to be exercised.