The pattern I used is very simple, I think you can guess it, but just in case and for my own further references, here it is:
Using 3.0mm hook, make ring.
1. 6 sc in ring
2. 2sc in every sc (12)
3. *1sc in sc, 2 sc in sc* around (18)
4. sc around
5. sc around
6. sc around
7. *1sc in sc, sc2tog* around (12)
-- stuff the ball --
8. sc2tog around (6)
Cut yarn, thread through the 6 remaining stitches and pull to close the hole. Weave in the end.