I use three dodging tools:

1. A flat piece of black opaque paper that bends. I can make all sorts of shapes with it, as well as angle it so that it becomes just a thin 'string' shadow on the paper surface. Sky is the limit with this tool.
2. A round piece of opaque paper, about 1.5inch diameter, taped to a piece of metal wire. I can make a round shape, or an oval shape with this. I also use it to dodge bigger areas by holding it close to the print surface and moving it around.
3. My hands. As has been mentioned, it is surprising what shapes you can contort your hands to become, as a shadow.

I have never felt that I need anything else.