You need to review your work. Seems like a simple statement, yet one that I have sometimes overlooked. Sometimes I get so involved in a pattern, enjoying the process; they way the stitches work together, the way the yarn feels, the rhythm of the movement. Then when I finally sit back and look at my work, I realize that I made a mistake way back at the beginning. So the re-work process begins again.
Here is my most recent “why didn’t I pay more attention” project. I was working up a shawl in a miter triangle, but have not been working my decreases correctly and thus have something more like a miter square (or trapezoid, it is all up for matter of personal preference). I really enjoy the stitch pattern (and hope to have it available very soon), and love the yarn (Lisa Souza Baby Alpaca/Silk, what is not to love), so it easily puts me into a trance.
So now it is time to pay a little more attention, and work my math a little more.