First click on your 'my account' page. Then you can click on 'Title Tuner'. Any Hubs you have written that "Title Tuner' has a suggestion for improving will be listed. If you click on a Hub title there, you will get suggestions of words to add to your title. At the bottom of this page it says 'learning center'. Click on that link and you will find a list of topics about Hubpages. One of them is about 'Title Tuner'.