When you finish sewing your stuffed animal, you're usually left with a small hole that you need to stitch by hand. The best way to close these holes is to use to use straight stitches, from side to side. Start off on the top piece of fabric, insert your needle into the line of the seam allowance, and bring the needle back through the same piece of fabric a few mm away from where you first inserted the needle. Then repeat this on the bottom piece of fabric. Repeat on the top, and then the bottom piece of fabric, you'll notice a ladder of stitches forming. When you've finished, you can pull the stitches tight.