There are far better forums to learn about sculpture techniques than here.This is one of the best around
The Effects Lab In this forum you'll see peoples work that is so incredible its scary, real film industry professionals, no recasters just awesome talent. In answer to your smoothing question, it depends on the clay, if you're using a medium to soft oil wax/oil clay then you need rakes, start with a large one and work your way down to a very fine one this will work out all the depressions left by your fingers, using rubbing alchohol or turps is only for certain techniques , it will turn the surface of your sculpt into an oily mess if not used correctly. Most professional sculptors use very hard wax for doing mechanical/machined looking parts. Have a look around for sites that talk about various techniques for using chavant. Chavants web page contains some really good information about which clay to use for certain types of projects, and how to achive various finishes on the clay surface.