What is the best for seo of the following:

1. using <h1>keyword</h1> in layout and putting each subpage title in </h2>
2. using <h1>keyword</h1> only for main page and on each subpage replace it to <h2>keyword</h2> and using h1 tags for subapge title
3. not using <h1>keyword</h1> on any of the pages instead put keyword in

   in header and use for each subpage and using <h1>keyword + something for main page title</h1>

4. None of the above (please go into as much details)