It depends on what kind of look and feel you are going for. If you’re on the Rhino 7 beta you can use the sub-d tools to make some basic, decent “cartoon-ey” type of things, same was was done with T-Splines when that was a thing. But if you want more detail than that you’re far better off on a different software - zbrush or something like that. While the V7 renderer looks promising too, you’ll be quite limited in what kind of texture mapping you can do, unless you send your model out to Substance Painter or something like that.
ETA - this is a good example of the look and feel that V7/sub-d can create: