You will need:
a pair of earwires
2 bead caps
felting needle and foam pad/ felting mat
awl/ large eyed needle
round nose pliers
1) Roll the wool fibre with your finger to create a ball.
2) Place the fibre between your palms and roll it so that the fibre holds together (do not worry if the ball does not look like a perfect ball). Lay the ball on your felting mat and poke it with the felting needle from every angle. Only move your needle straight up and down; if you move your needle sideways, the tip will break. And be careful not to poke your fingers!
To quicken the felting process, I use this three-needles-stuck-in-one needle to start with. Yes, as you can see, it is just three felting needles stuck in one with a rubber band :) I switch to a single needle for finishing touches.
3) Keep poking until the fibre is compressed, and roll the ball between your palms time to time to make it perfectly round.
4) When the ball is nicely felted, place the bead cap to make sure it fits nicely.
5) Poke a hole through the ball with an awl or large eyed needle.
6) Thread the head pin through the ball.
7) Thread the head pin through the bead cap, and bend the head pin at abut 60 degree angle.
8) Using round nose pliers, bend the wire into a loop, and cut the excess wire with wire cutters.
9) With round nose pliers, open the loop of the earwire.
10) Assemble the loop to the earwire.
11) Close the loop of the earwire with pliers, and you are done!