I tend to cut out masks that represent the area I'm dodging (or burning) and some of them can be quite intricate. These are attached to very thin bits of wire used for flower arranging purposes. They are used close to the paper and moved enough to hide the wire shadow and to eliminate any harsh change in tone. If you angle the wire such that it isn't in direct contact with the paper, you can virtually avoid any chance of it casting a shadow. I have, on occasion, used various parts of my anatomy as dodging tools but I can't manage to keep the required shape long enough