I had a little play yesterday with transfer inks. They work on polyester fabrics, also on a polyester mix but less well - it absorbs less of the ink. It works so well on Evolon (a woven polyester fabric) which is the heart labelled number 2. I also used the Evolon with the plant material.
I've also made some organza flowers, one made using a tea-light to shrivel the edges of the organza and the other 2 using a heatgun.