Yes, I'm a spell-spinner. You know how to spin spells, don't you? No?
Okay, then, I'll tell you.
First, you'll need some harvested magic. You can buy pre-packaged magic at most any Craft store, but I like to harvest my own. Some people say it doesn't make a difference, but most of the best spell-weavers say you get better results if you can do all the steps yourself. You should at least know how to harvest.
To harvest, you start by combing all the old unabsorbed wild magic out of your aura. You might be able to use some of that to spin, but usually if it's been tangled up in your aura for a while it'll be too friable to work with. So, look at your aura. See those little things floating around in it, like bits of glittery fur drifting below the surface of a lake? Yes, those. Comb them all out. You can use an aura comb or your fingers -- I always use an aura comb for this part. Once you've gotten all of the bits out, throw them away, unless you want to try salvaging them to spin.
Next, get dressed up in your shiniest clothing. Yes, really. Why do you think the stereotype of a wizard has him wearing a robe covered in stars? Magic is attracted to glitter and shine, so you want to wear something with a lot of gleam to it. You don't need to go totally overboard here -- sequins head to toe are overkill. It won't hurt, mind you, but a vinyl outfit with some polished studs or an evening dress with a nice pattern of rhinestones is just as good. Expensive jewelry is fine, but so is cheap junk as long as it shines. So you want glossy gold and silver tones, for instance, not buff ones. Magic doesn't have particularly good taste.
Now, clench your aura down tight. Pull it in as close to your body as you can. No, tighter than that. As if you were trying to stop someone else from using a spell on you. Didn't you ever get into spell fights when you were a kid? You don't want your aura loose and soft and open like translucent smoke drifting around you, but tight, hard, closed, like a layer of polished glass covering your skin. Yes, that's better. Practice at it, it's a good skill to have even if you're not harvesting magic.
And now you're ready to gather magic! Go out for a walk. Anywhere, it doesn't matter. Okay, it does kind of matter. You'll get different flavors of wild magic depending on where you walk around. The flavor at a goth night club (which may be where you think you belong, dressed like that) isn't the same as the flavor on a city street, and it's nothing like the flavor on a farm, which is totally unlike that of a rainforest or a nature preserve. Every place's magic is different. But it's all still magic, and for most spells it's not going to make much difference. Also, don't worry about looking for a place where no one else is harvesting. Magic is like air: it'll flow to whereever the magic-pressure is low. You're not going to run out of magic to harvest by because you're surrounded by harvesters any more than you'll run out of air to breathe because you're in a crowd full of people breathing. It's not a scarce resource.
Anyway, as you're walking around, you'll notice bits of glittery wild magic start to accumulate on the outside of your aura. Gradually, they'll build up from dust motes to clumps, and if you keep at it long enough your aura will end up covered in raw magic and to second sight you'll look like a wookie that went to war with a glitter factory and lost. But unless you're really really good, you'll get tired of keeping your aura clenched in before the covering gets anywhere near that thick.
When you're starting to get tired of keeping your aura closed, pull the wild magic off of it. You can use an aura comb for this, too, but I never do. Fresh wild magic comes off easily in your fingers, and unless you have a very expensive professional-quality comb, aura combs will change the flavor of the magic in a subtle and usually not particularly good way. The clumps of magic should come off easily in your hands: just curl your fingers and rake them over all the clusters and loose bits. You need to keep your aura closed while you do this, too, otherwise the magic will start to dissolve in your aura. So don't wait until you're too tired to clench your aura any more! Don't worry if you get tired quickly in the beginning, it gets a lot easier with practice.
Once you've gathered all the wild magic into a big bundle, you can store it by wrapping it up in something shiny. Tinfoil works fine: be sure to wrap it with the reflective side facing in. Or you can buy the bright cellophane bags that packaged magic comes in -- any good Craft store will sell the bags by themselves in boxes of a hundred. Or tie it up with spells you're not using for anything else. Or you can start spinning it right away. Just remember to wrap up any leftover magic so it doesn't dissipate.
Before you start spinning, set aside a good-sized clump of harvested magic, maybe twice the size of your head. If you've tied it up with spells, undo enough of them that you can pull it out easily. Or unwrap one side if it's wrapped or bagged. Now, you'll need to make a vortex with your aura. There are lots of ways to do this, so I'm only going to explain one. And for pity's sake, don't use one of those mechanical-based vortex-generators, if you're going to use those you might as well just buy bulk spells, why bother making your own?
Start by relaxing your aura all the way. Loosen it up. Breathe. Chill. Meditate on your navel. Contemplate the universe. Embrace your surroundings. Whatever works for you. Once your aura is spread out around you, swirl your hand through the aura before your chest, over and over again, in the same direction. Yes, it's just like making a whirlpool in a bathtub. Yes, you can do it widdershins if that makes you happy, but the direction doesn’t matter. Make sure you swirl so that you can reach both the top and the tip of the vortex easily: the top is going to be a little above your wrist/elbow, depending how much of your arm you manage to swirl, and the tip will be below your fingers: bigger swirls make the tip lower down. If you pinwheel your whole arm, which I'm not recommending for beginners, you'll end up with the tip by your shoulder and the top past your hand. This is annoying to work with, though it's easy to make a vortex like that. For thick, sturdy spells, a wide slow vortex is best: for quick nimble ones, you want a narrow fast one.
Once you've got a nice vortex going, feed some of your harvested magic into the top with one hand -- if you're right handed, you’ll probably want to use your left for this. Don’t be too slow about getting it from your hand to the vortex, because if the harvested magic spends too long in contact with your open aura it’ll start to absorb. Once you get the magic to the top of the vortex, it’ll along towards the vortex tip. Put your right hand by the tip and be prepared to catch it between your thumb and forefinger. The vortex will taper it most of the way, but you need to use your fingers to smooth the thread of the spell and make sure it’s of uniform thickness. You can twist it a little extra to keep it nice and tight and make sure it coheres well. Keep feeding in magic until the vortex starts to slow noticeably. Then you’ll want to nip off the spell you’ve been spinning so you can restart the vortex. Or take a break, as you prefer.
And that’s all there is to it! The theory’s pretty easy, the tricky parts aren’t so much doing it as doing it well.
Hmm? What do you do with the spun spell? Well, that’s up to you, isn’t it?
This is a meme of sorts, started by haikujaguar. It's a way to make exercise more interesting by imagining it as a metaphor for something extraordinary. haikujaguar uses a metaphor of "minutes exercised: alien bugs killed". minor_architect uses "minutes exercised: people rescued". dulcinbradbury does yoga and her metaphor is "ambassador to an alien race". Mine is "minutes: spells spun". It took me ages to finish this after deciding on the metaphor, so I don't know that I'll be doing as much with it as the other people I know who are doing the meme. :)