T-Splines is a powerful solution for creating organic forms. You’ll be amazed at what can be accomplished with the program.
http://www.youtube.com/watch?feature=player_embedded&v=9kYdmBfmh4M
Basic T-Splines Tutorials: http://www.tsplines.com/support/basictutorials.html
Advanced T-Splines Tutorials: https://www.tsplines.com/store/tstutorials.html