Schematically correct Markup and SEO

Website structure is important for SEO. I find out a lot of people including myself is guily for not correctly structuring websites schematically. For SEO websites should contain h1, h2, p , strong and other elements to scructure a document. I am sure alot of people are guilty for this, including me applying h* tags to make text bigger.

I noticed an issue about one of our website rankings were dropping, we included lots of key text phrases, everything we thought had been done right and could not think of a way why our ranking were doing below average.

I looked at the structure, what was behind the scenes within the HTML language. As I found that the admin was using his updatable website to present all his text in h1 format. Thus givng priority over h2. So when google comes to check for keywords within the title tags it was seeing paragraphs of text with random works instead of just a few words which tells google the purpose of page.

While our site was great from a user point of view, schematically, it was very bad.  I have found alot of people having this problem but it is easy to get sidetracked. Another issue is using strong tags on text for styling rather than emphasising.  font-weight: bold and <strong> are very different regarding to structure.