7 Knitting Mistakes & How to Fix them

The solution: the working yarn (the yarn that is connected to the ball) is hanging on the last stitch you knitted. Make sure that this stitch is on your right needle when you start.

There can be several reasons for this:
Cause #1: You may be sewing the stitches on the tapered part of your needle.
Solution: Make sure you move your stitches back to the widest part of the needle each time you sew a new stitch.

Cause #2: You may be tightening each stitch after working by tugging on the yarn.
Solution: Do not do this. Instead, hold the yarn loosely and gently lift the right needle for each new stitch to increase it slightly.

Cause #3: You may be holding the yarn tension too tight. Are you wrapping the working yarn around your fingers?
Solution: Try to find a comfortable tension when holding your yarn, or just try to hold it looser in your palm.

(OR there are too many stitches; you have an extra stitch).
Cause: You may have accidentally knit twice in the first stitch.
If you are new to knitting, you may have accidentally increased a stitch at the beginning of a row. The first and/or last stitch of a row may be looser than the others, and sometimes turns over so that the two legs of the stitch below are closer to the needle. You may have worked into the legs of the stitch under the first stitch as it turned around the needle.
Solution: You have 3 options:
If it is an edge that will be sewn into a seam later, you can just take it off again as soon as you notice it. Mark the spot where you had the extra stitch. When you sew the garment, pick up the extra stitch at that point in the seam allowance.
If it bothers you to leave it there, you can drop the second stitch off the needle and unravel it to where the unwanted increase occurred. Spread the excess yarn over the adjacent stitches. The edge stitch will likely be looser here.
Unravel your knit to the point where the mistake was made, and continue from there.

Solution: if you dropped a stitch, simply pinch just below the stitch to keep it from unravelling. Pick it back up by inserting the tip of the left needle into the dropped stitch from the front.

Cause: You may not be keeping the tension of your working yarn even. Some stitches are loose and others are tight, making your knitted piece look uneven.
Solution: If you are new to knitting, this is a common problem that will improve with practise. The key is to find a comfortable and consistent way to hold your yarn. Washing and blocking your work can also help make your knitting more consistent.

The cause: when you knit the last stitch of the previous row, the yarn somehow slipped and was never pulled through to form a new stitch.
Solution: turn your work over as if you were finishing the last row. Put the last stitch back on the left needle and knit it again. Now you can turn your work over and start the new row.

Cause: Incomplete Stitch: You put your needle into the stitch and wrapped the yarn around the needle, but you pulled the old stitch off the left needle without pulling the new stitch through. Both the old stitch and the new stitch are on your right needle.
Solution: slip the intervening stitches back onto the left needle, or knit off the intervening stitches and put them back onto the left needle. Knit the stitch again and make sure you finish the new stitch.