I know how headings are supposed to work, but in any single text I never get to use anything more than the H1.
A few years back, in some magazine-style sites, I saw this practice where H2 to H6 headings were used as excerpt titles - links to other articles. I started doing the same myself, without really knowing how proper the code is (as there is no direct hierarchy, just an implied sense of importance).
So, for example, I would use H1 to wrap the title of the main article, than a couple of H2s for the "previous post" and "next post" titles, a few more H3s for titles of "articles in the same category" and so on.
Validators seem to be ok with it, but still I'm not sure if it's fine semantically or seo-wise. Does it make sense or is it stupid?