Admittedly, this is like giving away my best secret ever. Here goes:
My absolute favorite pencil of all time is
These pencils can be bit hard to come by. I stumbled upon them when living in Israel. Most of their art supplies come from Holland or Germany.
The thing that makes these pencils so special is that they literally melt when coming into contact with water. What's more, they don't become watery as you would expect. It becomes kind of like paint, but it seeps right into the fabric immediately. When you spray the doll's face with water and color the pencil on, it works like magic. Shading is a dream with these pencils. I find myself dipping the white pencil in water and blending right over darker colors. I get wonderful results that I could never achieve with other pencil.