Follow these easy instructions from @hanahorack ...and try out some natural dyes.
Pomegranate and Onion will naturally bond with the fabric so they are easy to start with. If you cook the liquid for longer it will become more concentrated and be more suitable for using as an ink. The process will work on wool and silk, but not man-made fibres or cotton. Cotton needs to prepared first.
You can try this with any plants (be careful of poisonous ones). Many do not give permanent results. Mullein, Oak, Goldenrod, Olive, Eucalyptus, Rosemary, Yarrow, Ferns, Tree barks are just some examples. You may need to MORDANT the fabric first for these and other dyes, because they do not all naturally form a permanent bond with the fabric. Vinegar is a mordant that most people have, also salt. Frequently used is ALUM, you can get this online or from the chemist. We will post another tutorial about using mordants.
Some fibres dyed with natural plant materials. Images on the left: rose petals, oak, yarrow and mahonia berries. The bottom right image shows pomegranate and onion dyes. Colours vary according to season and plant. You can dye fibres more than once to develop different shades and tones.