There are two basic ways to work with wires, the "cold" way or with heating the wire. You heat the wire - metal in in order to soften it, because it is too hard to work "cold".
The wires I use are usually flexible to some degree, meaning they are not too soft and not too hard to manipulate. The lower the Gauge, the harder they are to work. On the other hand, some wires are too flexible and thus quite hard to twist and work with. Other wires are so soft that once done with, the image you created is very vulnerable and could be damaged easily.
For most of the wires I use, flexibility is there and some mistakes during the process can be undone, in some cases at least. Still you can’t take a piece of wire, bend or fold it and then unfold and have a straight piece of wire again. Some marks will remain to be handled further or hidden.
Often I'm asked which wire to use. What I try to do is let the asker test a few wires and decide for himself which is more comfortable for him to work with. As He, or she tries the wires, they understand along the process, advantages and disadvantages of each wire and can decide which one is best suited for their use.