Hi Stardust, you might check out some Rhino tutorials to get some good ideas:
https://vimeo.com/111593972
https://www.youtube.com/watch?v=pZy_2wNt0Eg

And here's a previous thread:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4566.1

Pilou's method from here looks pretty good:
http://moi3d.com/forum/index.php?webtag=MOI&msg=718.1

- Michael