What's Keeping Me Warm, Part Two

I started this scarf back in February, put it away for the summer, and pulled it out a few weeks ago. I had just as much trouble ending it as I had starting it. The pattern was a chart and not only left lots of details to the imagination, but also had an error or two. On a decrease row near the end, I had one too few stitches at the end of the row. After frogging back a couple of rows twice, I allowed that maybe, possibly, the pattern was wrong. It occurred to me that The Best Knitting Book Ever had explained about lifelines, so I used the technique for the first time with great success. Admittedly, it was only a scarf and not difficult to frog, but still, I saw how useful this technique could be. Just take a spare piece of yarn and use a yarn needle to thread it through the row just knitted. Then knit on. And if you do end up frogging, you can easily pick up the stitches held by the spare yarn. I knit several rows several times, frogging back to my lifeline, until I figured out how to correct the error on the pattern.