I've been wanting to try my hand on pencil sculpting for a long time and I have finally done it! hehehe it IS my first one---so there are flaws 7.7 BUT it was fun nevertheless. Of course it took a few tries and I ended up having a few 'practice runs' because I had no idea what i was doing.
Oh you wouldn't believe how many times the light on the top of the Tardis would just snap off! O:< anyways- if you have good lighting a sharp blade and some pencils you don't mind ruining- go for it