How do I get my jewelry wire to be the right stiffness?
There are three grades of hardness in jewellery wire:


Full-hard, which is tempered wire that is very stiff. It's rarely used, because it's just too stiff for most jewellery.
Half-hard, which is hardened during manufacture but is not fully tempered and is not so hard. It's pliable by hand, but you need to use some force to do it and pliers are often easier. This is the stuff you want for most jewellery (excluding things that need to bend such as necklaces (though you should be looking at chain for those anyway)).
Dead-soft, which is just plain wire that hasn't been at all hardened. This needs minimal force from your hands to bend. I suspect you've been buying this kind of stuff.


The hardness also depends to an extent on the material - the cheaper stuff like copper and brass is generally manufactured at softer grades.

Bear in mind that you can also harden existing soft wire by either applying heat to it (i.e. a blow-torch or other high-intensity heat - a match won't do it) and then quenching it (drop it straight into cold water), or applying pressure to it (hammer it - just remember that this also reduces the diameter).

You can ask when you're buying the wire what grade it is, or look on whatever packaging it comes in to see if it's marked.