"If we take into account that mankind has been farming sheep for more than 10,000 years, it could be speculated that feltmaking was discovered relatively soon afterwards."
The most basic requirements for feltmaking: heat, moisture, & friction.
This could get a bit messy, so it would be wise to work outside, in your kitchen, or bathroom.
...You should get a pot of water boiling while you work on laying out the fibers.
To begin, the materials necessary to make felt are:
-Carded wool roving or untreated knitting yarn
-Two pieces of fine tulle fabric, about 10x10 inches
(depending on how much fabric your making)
1. Begin by placing your first layer of tulle on a flat surface.
2. Lay out a fairly even layer of fiber on this piece of tulle.
Try to keep the threads running in the same direction and avoid creating bulky spots or holes.
3. Lay another layer of wool on top of the first,
changing the direction of threads so that the new layer is perpendicular to the first.
Repeat the same process several times, alternating the direction each time.
You will end up with something like this...
Now you can work on the decoration...
4. Arrange larger areas of colors/smaller details
Some practice may be necessary before you master this stage.
Your final fabric may end up quite different after the felting process than you initially imagine,
but these surprises can be cool too!
5. After you are ready to move on, place the second layer of tulle on top of your work.
6. Fold the fabric over on both the right & left sides
(make sure your work is in the center of these folds)
7. Place your work into your kitchen sink/bathtub/container/whatever works
8. Pour a small amount of liquid soap onto your work.
9. Now, take a cup-full of boiling water at a time,
and pour this on top of your work until the front side is saturated.
10. Then you may splash your work with warm water,
pick it up, rinse some of the soap a bit,
rub it together and create some friction.
Eventually, flip your work so the opposite side faces upwards.
Repeat the same process, saturating the back side in boiling water,
then rinsing the soap out of the wool.
(all while contained inside of the layers of tulle)
11. Once you have rinsed your work, place it on top of a dish towel,
then roll the towel up with your work inside and squeeze all of the water out.
12. Unroll your towel and peel away the layer of tulle to reveal your work!