Thanks for pointing me in the right direction for the pattern! It was quite simple and I have the felted clogs drying on my feet as we speak.
I used a denim colour White Buffalo unspun yarn and it felts very nicely. I only needed two short (hot) wash cycles, pulled them into shape and put them on to dry. I think I'll be making lots of these for gifts. ;>)
Here are links to two pictures - one before and one after: