One of the most useful tool for a jeweller that does any metalwork, wax carving or other similar work is a bench peg - this is a piece of wood that is clamped to your desk or table and used to support your work.
A Bench Peg - How does it help?
You can cut the peg with different shaped notches to allow you to do different tasks. Most people cut a V shape into them - this can be used when cutting metal - your metal sits across the peg - supported on each side of the V, and you can cut in the slot.
You can rest your work on the peg to support it while you are filing, drilling, sanding, polishing or shaping it - being able to support your piece while you work allows you much more control and to be able to put more pressure and work more efficiently. Using a peg rather than the edge of a table allows you free-er access to be able to work at different angles, and is easily replaceable when it wears out.
By cutting smaller slots or drilling holes through the peg, you can use it to wedge or hold your work - and to allow you to position things at useful angles for you.
You can get a variety of bench pegs from any jewellery supplies store - you can get plain pegs, ones with shapes ready cut out, or you can get them with their own clamps, including ones that incorporate a steel block, which is another very useful tool. Some jewellers benches incorporate a specially made slot to accomodate a peg, but you can clamp a peg onto any table or bench, allowing you extra flexibility, especially if working at home.