I ended up spinning about 1.5 ounces of fiber onto each spindle. The white fiber on the top-whorl spindle below is Bluefaced Leicester, and the red fiber on the bottom-whorl spindle is merino (you can view larger versions of the pictures by clicking on them):
Once I had spun the fiber up, I decided to ply it right from the spindles, using my spinning wheel (I have a Kromski Fantasia). Here's my set-up for plying:
I'm not finished plying yet, but here's what's on the bobbin already:
I call it Candy Cane yarn. I've made it before with my wheel. I really like it. I made a pair of mittens with it that look like crushed peppermint, and I sold a kit with enough yarn and a pattern for the mittens. It's really soft and yummy yarn.
Spinning with the drop spindles is a little addictive. I really like it, and as of right now, I don't have a preference between the top- and the bottom-whorl types. Spinning with a wheel is faster, but there's something really satisfying about the drop spindle. I'm looking forward to using them lots more in the future.
If you'd like to try spinning with drop spindles, I'd recommend the shop I've linked to above, and I'd recommend this book, by Priscilla A. Gibson-Roberts:
It deals mostly with the top-whorl spindle, but you'll pick up how to use the bottom-whorl as well. It recommended adding notches to your top whorl spindle if it doesn't already have them. Mine did not have notches and I did add one. I'll probably add at least one more. The notches really help keep the yarn in place, which is important as the amount of yarn wound around the spindle starts to become substantial.