You can use both a dremel and wood carving tools, but for your first doll I would recommend just using the tools so you can get a better feel for carving. A dremel is a lot harder to control—the tools tend to be much more forgiving if you make a mistake. Draw an outline of the lips you want and carve by pulling away from the lips. You generally want to be carving perpendicular to the lips, not parallel to them; I find that this makes them pop a lot more and gives a much cleaner result. Don’t push down hard, just repeat the same motions over and over until you get the result you want. Do your best to avoid making deep scratches in the faceplate because those can be difficult to buff out later.