It depends a lot on how much you will need to work the wire to get
it into its final shape. I have made jump rings and the like from
half hard silver wire, where I just used a round nosed plier and gave
the wire a single twist, and voila! A perfect ring. For making more
intricate shapes, situations where you need to bend the wire back and
forth more than a couple of times, or if you plan to hammer the wire,
soft wire is a better bet. The wire tends to harden as it is worked.
If you have half hard wire, and you need it softer, you can soften
it by annealing. Just heat it up and quench it.