Step 7: Sewing the Ears
So, you've flipped you monster inside-out. Now, lay it flat and line up the ears. (This is where pins come in handy: If you have an intricately patterned sock, you may want to pin it so that it lines up as you'd like.) To begin sewing, start on one side of the head and sew to the other. Basically, just don't start sewing somewhere in the middle.
Completing the stitch: Be sure to stop sewing with enough thread to tie-off the stitch. How much is enough thread? The easiest thing to do is on your last stich, make a loop and pass your needle through it (see image below.) Remember when we "doubled up" when we threaded the needle? Well, after you make your last stich and a loop to finish it off, pull the thread taut and cut both pieces as close to the needle as you can. Take those two pieces and tie them together (like when you're tying your shoes - sans the bow.) Double or triple-knot the threads to make your stitch really strong.