Summarize this article:

Insert the hook through the first stitch or space to be worked over.  The hook should not be attached to any yarn yet. Note that the right side of the piece should face toward you but the yarn should be at the back. Grab the yarn with your hook. Pull both the yarn and hook through to the front of the piece. You should have one loop on your hook after completing this step. Insert the hook into the stitch or space directly next to the one you first worked in. Yarn over the hook from back to front. In one motion, pull the yarn-over back through to the front of the work while also pulling it through the loop previously on your hook.  If this motion is too difficult for you to master, you can pull the yarn-over through to the front of the work first before pulling it through the loop on your hook. You've essentially just completed one chain stitch over the surface of the original piece, thereby securing the yarn in place. Insert the hook back into the second worked stitch and follow the same procedure to create another chain stitch. Repeat this as many times as needed to build the size dot you desire.  For a moderately sized dot, create three to five of these stitches. Each of these chain stitches must be worked over the same stitch of your original piece. When you're satisfied with the dot size, insert the hook through the stitch or space directly next to the one your chain stitches were worked into. Yarn over the hook from back to front, then pull this yarn-over back through to the front of the work while simultaneously pulling it through the loop already on your hook.  As before, you can pull the yarn-over through to the front of the work before pulling it through the loop if doing so is easier for you. This final chain stitch closes the dot. Cut the yarn, leaving a 4-inch (10-cm) tail. Pull this tail through the loop on your hook to finish and secure the stitch. Pull the loose tail of yarn back through to the back of the work and weave it into the underside of the piece to hide it. This step also provides the dot with further security.

Summary:
Insert the hook. Draw up a loop. Insert the hook into the next stitch. Chain one through the stitch. Repeat several times. Insert the hook into the next stitch. Chain one. Fasten off the yarn.