I've been getting into dying yarns for a while and love the ability to control color before you knit it into something.

But, I want to get a different texture with my yarns. I was thinking of moving into all natural dyes that I could add in to see what type of effect it would have on my yarn. Does anyone know some of the best ingredients to put together to experiment with this? And, if I wanted a plant instead of the powder, how I would I prepare it into a dye?