Never rush.
Deciding the shape your tree will take is a lifetime decision, so be sure to examine all angles and possibilities. Copper wire, though expensive, is most suitable for wiring a bonsai-to-be such as the juniper above, because it remains soft. Galvanized iron or plastic coated wire may be used, but they tend to look rather ugly and detract from your tree. Remember, the larger coniferous trees will be wearing their wires for 12 - 18 months, so please take care in choosing the best "look " for your bonsai.