What she said, but as an additional hint...if you have a cable needle or a big tapestry needle handy, you can put the misplaced cable stitches on that. If you were supposed to, say, slip three to the cable needle held behind the work and knit three, and you slipped three and held them in front instead...not that I've ever done such a thing maybe 46,000 times
...even if you don't usually use a cable needle, having one or a substitute handy makes it a lot easier to get things back where they belong.
You can also run a tapestry needle or cable needle or whatever through the stitches on the row below where you made the mistake, then pull out the wrong ones. If you're working on slick yarn or it's really tight, that helps keep them from escaping sometimes.