The last few times I've spun, I've chosen small amounts of roving and tried to spin a soft-spun singles yarn. It's tough--getting that balance between enough twist for it to hold together and just a bit too much so that it kinks back on itself. Plus getting the thickness even isn't easy when the wheel is set to draw the yarn in quickly!
Here's the finished skein, unwashed:
You can see that it's starting to kink back on itself a little bit, despite my best efforts. I'm getting better at it, though; this skein is definitely more even than my first attempt a few months ago. Practice, practice, practice!