I have a few modelling ideas for certian things
For High poly stuff.
Character modelling;
Box Modelling (Poly modelling works well, but is a wee bit tedious)
Car Modelling;
Polymodelling (this is how I do it, asked on a forum and Sspike confirmed it was a good way to do it as he does it)
Achitecture;
Box modelling
Plants;
Various ways, but box modelling and use alpha mapped objects for the leaves.
Hair;
Box modelling + Alpha maps, if you have the hair feature in your app, use that.
Terrian:
I use planes and a 'magnet tool' which works like Geoscape.
Fire;
Depending on your application, generally I would use a particle system, either emmit red and yellow visible lights, but red and yellow objects work too but don't give off light.
For those luckier people, can simply use the light object and make it into a fire by using 'Noise' I use Wave noise in cinema 4D and play with the contrasts to get the right effect.
Blood:
Metaball + Spheres + Particle emmiter, gives a nice blood spurting effect