I always do it. I finish one spinning project and immediately start another. And then don't work on it for many months. After finishing up the Sweet Georgia BFL last July, I started working on some pretty roving from KnittyandColor.
I ended up with about 190 yards/3.5 oz of a 3-ply. I call this my "sweet spot." I always end up with around the same amount every time I spin! I spin so infrequently I haven't been too worried about trying to get thinner singles. I just spin when I feel like spinning and what I get, I get. :)
As is it is the cycle, I started something new on the wheel! Hopefully it won't be almost a year before I'm posting photos on the blog (but I wouldn't be surprised if it was).