First step is putting the material together and tying it tightly in variations of five basic shapes, known as rosettes, bunches, gathers, pleats and marblings. String or dental floss can be used to tie it, but elastic is best, as it is not permeated by the dye and can be easily snipped free. The fabric is then immersed in the simmering (not boiling) dye solution and kept there for a length of time that varies with the material; cotton, for instance, soaks up the dye slowly, while silk takes it quickly. Next, the fabric is rinsed in cold water. The process can be repeated as many as five times, using a different color for each dyeing. Shadings of color can be achieved by boiling in a color remover or stretching the fabric on the floor and rubbing on chlorine bleach (which has to be removed in a washing machine). Dazzling variations can be created by twisting the elastic around the bunched material and using a medicine dropper or squeeze bottle to drop the dye into folds and crevices of the cloth.
"Although many different kinds of dyes may be used, most tie-dyers now dye with Procion MX fiber reactive dyes.This class of dyes works at warm room temperatures; the molecules permanently bind with cellulose based fibers (cotton, rayon, hemp, linen), as well as silk, when the pH is raised. Soda ash (sodium carbonate) is generally used to raise the pH and is either added directly to the dye, or in a solution of water in which garments are soaked before dyeing. They do not fade with washing, but sunlight will cause the colors to fade over time" (Wikipedia)
Though tie dyes appear to be "easy" to make, they are somewhat complex thus the reason for each work of tie dye art being unique. Enjoy your psychedelic clothing and remain UNIQUE.