After reading a thread on the Rav in Spinner Central about corespinning, I decided to try it during the Tour de Fleece. Hobbledehoy has a video tutorial about it, but for anyone who would rather be able to read or print out instructions, it goes something like this:
-Spin a single that you like.
-Wind the thread/yarn/crochet cotton that you'll use for your core onto a drop spindle.
-Put your biggest bobbin onto the wheel, along with the flyer.
-Set the drive band on the largest (slowest) whirl.
-Attach the end of your core thread to the leader.
-Unwind enough thread from the bobbin that the spindle can spin freely, hanging from the thread in your left hand.
-Start spinning very slowly in the opposite direction from the way the single was spun, attaching the single to the core thread (just let it start to wrap itself around it) Hold the single at an 80 to 90 degree angle to the core, and when you see the core between the wraps of the single, push the single up the thread.
-Let the core thread turn freely in your hand to unwind the twist- it was already stable and if you add too much more twist, the yarn will kink up!

And just keep going until you're out of single, core, or patience with the project! (I found that sub-laceweight singles were NOT a good choice for this! It took way too long to spin only about 70 feet of yarn. Next time I'll try something heavier!