Yes I saw a guy making baskets at a show too, maybe the same one, he made It look ridiculously easy!
Woodbodger, if you get a chance to read Mike Abbot's description of how to cleave in his living woods book, it kind of makes sense of the theory, but yes I think it is, as Toby say, practice...
Actually I was thinking today as I was cutting some tent pegs from chestnut that one of the most satifying sounds (in my small world!) is the kind of 'plink' you get as a dead straight grained bit of wood splits and springs off! Another is the smell ahh...