As a new spinner I tended to focus on trying to spin thinner (ie more yardage) and more consistent yarns, and always went with 2-ply. I just didn't feel confident enough to tackle a single ply yarn, and didn't want to "waste" yardage making a 3-ply yarn. But lately, I've been trying to branch out of my comfort zone a bit, after all, handspun yarn isn't supposed to always try to look like mill spun, it's uniqueness is it's charm. And some looks are better achieved using different spinning techniques.
This summer I worked on spinning singles yarns. Singles yarns are a bit of a challenge for two reasons. First, you have to get the twist just right, too much twist and your yarn is still a curly mess after washing, not enough and your yarn falls apart; without that second ply to stabilize the twist it can just be more difficult to work with. Secondly, if you want a consistent thichness yarn you have to concentrate just a bit more in the spinning as you cant count on a 2nd ply helping to even out the pits that are a little thicker or thinner than the rest, or if you want a thick & thin yarn you have to re-train your fingers (that are now used to spinning thin and even) to draft a little more unevenly and allow the slubby bits through).
I still need to take on the challenges of n-ply yarns, and art yarns like corespun and super coils (though I think I probably need the bulky flier for my wheel before I try coil yarns again, that was a bit of a mess).
So what new techniques do you want to learn as a spinner?