Help! How do you go back to fix mistakes or pick up dropped stitches?
One of the most useful things I've learned is to repair my knitting with a crochet hook. As you may have noticed, when you drop a stitch off the needle it can create a "ladder" as the loops from previous rows slip out of the ones above. To repair this, first stop the ladder from unravelling any further by putting a stitch holder, safety pin, paper clip or whatever through the last good stitch. Then knit to the point where the ladder is between your two needles and using the hook start drawing each "rung" of the ladder through the loop on the row below. By pulling it through from back to front you creat a knit stitch; pulling from front to back creates a purl stitch. When you reach the top row, slip the stitch onto the needle and you're ready to continue knitting.
If you drop a stitch and continue knitting without noticing, you can repair it in the same way. Treat the horizontal yarn between stitches just as you would the ladder, and draw the yarn from each missed row through the loop from the previous row until you have created a new stitch in each row all the way to the top. They will seem a little tight and may distort the adjacent stitches, but usually the tension will even out as you work with your project and when you wash it, so in the end you won't even be able to see the correction.
You can create a ladder intentionally in order to change a mistake in a previous row. Just be sure to secure the last "good" stitch before you start so that you don't have to repair more than necessary. By studying other parts of your knitting and patiently recreating the stitches with your crochet hook, you can even correct very complicated patterns. If you get hopelessly frustrated, it's sometimes best to put it aside and come back later.
I've always said a knitter's best friend is his crochet hook!
I've got knitting fever in the worsted way.
Never trust a man who, when left alone in a room with a tea cozy, doesn't try it on. ~Billy Connolly
And, it's easier for me, when I drop a purl stitch, merely turn the work around and treat it as a knit stitch. Then I don't have to remember which way to pull it from.
"If a man has cream at home in the refrigerator he won't go out looking for 2% butterfat"