Hi NaN, there is some information here for people coming from a poly modeling background:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4865.2

A couple of things are - try to use 2D profile curves and cutting things using boolean operations rather than trying to patch in surfaces on a 3D wire scaffolding and it's more common to construct things directly in place instead of say starting with a box and mutating its points into some other shape.

- Michael