During my first few days of playing with Sculptris, I toyed with various methods of building the base, high-res mesh. Many online tutorials involving ZBrush and friends present a workflow wherein the artist creates a very rough base mesh in another program, or globs together a very rough base mesh in ZBrush from which to obtain a surface to begin with. So I tried a few experiments with roughing-out a shape in Blender using metaballs or sub-surfaced extruded cube meshes, with mixed results. The idea is, of course, sound.... providing you have a very clear idea of your end result. I'm not very skilled at sketching freehand, so I currently don't have any kind of concept sketches from which to work. So, for this test model, I worked purely within Sculptris, starting with the default sphere and using G with large brush sizes to quickly rough-out the shape. Not having concept sketches, this method was probably the best for me. Even with a concept sketch, though, I could see this being a decent workflow to start. The rough shaping of a mesh using G is very fluid and free-form, and intuitive. I can pull out 'tendrils' using G, then use C (inflate) to blow them up and shape them as needed, with the detail slider set mid-range so that detail is added as the tendril inflates.
With Turtle Dude, I used G to squash the starting sphere, went into Draw mode (D) and roughed in the shape of the shell, depressed a few concavities for armholes, headhole, tailhole, etc... then used G to draw out tendrils for each extremity. C inflated them up to roughly the proportions I needed, then from there it was just simple refinement: a crease here, a smooth there, etc... All in all, the process worked very well, and I was able to achieve decent results fairly quickly. Total time spent, from base sphere to final low-poly textured version (minus rig and animation, which are still in progress) was about 3 or 4 hours, and a good chunk of that was spent fiddling with lights and re-baking the low-poly texture. The initial sculpting job was still fairly low-res compared to some examples I have seen online, but my lappy simply can not handle meshes in excess of about 500k tris or so. Plus, considering the scale of my current game project, more detail probably isn't necessary.
In the future, I would like to upgrade my hardware so that I can play with normal-mapped models in-game. Currently, I don't bother baking a normal map, and just do a texture bake with shading, diffuse, and ambient occlusion all into a single colormap texture. The obvious results of this are visible in the flattening of the bumps on the shell, the flattening and obscuring of the scale patterns, etc...
I'm really starting to enjoy this process, now that I'm getting a little confidence under my belt. I might even go so far as to say I enjoy it more than programming.