One important thing on sculpture model is tools. You need the tools for sculpture, scratch and build expect shape. My suggestion for choosing the tools of sculpture anime model should start with a art knife, brush and dental tools. You can see my tools below. If you can't find something like dental tools, you can use pencil or hard wood slim stick and scratch one side to your expectant shape. Don't forget to sand it by sandpaper number 500 and 1000. your major tool must always smooth serface. For the second shape of dental tool from the left, you can use sharp side of dividers instead. Dental tools is used to sprad out exceed material or sculpture surface of your model. Another important tool is brush. You really need bush to eliminate some dust on your art work after you scratch surface by art knife or sandpaper.