How do you make eco friendly dye for fabrics?

Experiment with tea. Various colors.

Teas work great, onion skins will die fabric, either beige using yellow onions or purple using red onions, you can use berries. There are all kinds of beautiful natural dyes. Dandelion flowers will make a pretty pale yellow.

It isn't too hard to make you own dyes or to purchase "natural and/or vegetable dye online or at craft shops that have dye goods.

Here red is a link to some fruits, veggies and other plants that work as dyes.

http://www.allnaturaldyeing.com/natural-dye-colors/

It can be great fun dying with natural ingredients, the result wll vary depending upon the fabric you are using and the mordant.

http://www.wildcolours.co.uk/html/natural_dyes_mordants.html

Here are a few suggestions: https://www.diynatural.com/natural-fabric-dyes/