--Easy Shell Tutorial--
Usually is not so hard create a snail shell..overall because lot of software have the seashell tool..but btw if you've found in trouble on make one...here a simple tut for a easy shell
1.Create a spiral spline..
2.This step could be slighty different for any 3d software.If you use Lightwave 3d i advise to use the great (and FREE) plug-in PICTRIX C_Worm_Lt,it's great for any kind of extrusion work!
For use it just keep the spline created in step one in the background and activate the plugin in a foreground layer,then play with settings.
If you don't use Lightwave try to to get a similar extrusion like the image below!
3.Just move points and polygons with a good offset to get a good result.
Use some reference to work well.
My last advice (and maybe the most important) is to create the UV before extruding or mapping your shell will be really hard!
If you'll use "Worm LT" don't worry the Uvmap creation will be automatic!