I worked at Purl, our knitting store, for a few years before Purl Patchwork opened. One of the mantras I was always telling beginning knitters was, "don't worry you can always rip it out." In other words, there was no permanent mistake, everything could be easily unraveled and tried again.
However, I never thought of sewing this way until recently. I approached ripping out seams with brute force and no technique, sometimes using scissors, sometimes using the dull seam ripper that came with my machine. Every time I tried to rip out a seam I ended up with pulled fabric and a chewed up looking edge. For this reason the ultra sharp Seam Ripper was a revelation. Joelle showed me the proper (and much easier) way to rip out a seam and I haven't looked back. None of my more ambitious projects would have come out well without it!
Follow the pictures below to see this totally simple, totally useful little tool at work:
Here is the offending seam.
Stick the sharp tip of the seam ripper under every other stitch along the seam and push through the thread, breaking it.
Once you've ripped every other stitch along the entire length of the seam simply pull the thread on the other side of the seam. It should come off of the fabric with very little pressure.
And Voila, the seam is gone. All you need to do is brush away the little bits of thread and try again. It's so freeing to realize that no seam is permanent!