It's really important when you make wire jewellery that it is made to last. While it's much easier to work with higher gauges and softer metal, they do then require a bit of effort to make them stay in the position you bent them into.
Fortunately it is reasonably simple to harden the metal. It actually already hardens as you work with it. Polishing it with an antivarnish cloth will also do the trick as will hammering the metal gently.
I have just bought a nylon hammer which allowed me to harden the necklace above without flattening the wire. A metal hammer will flatten the wire which can be a great effect, but I didn't want it for this piece.
