To be honest, that article is way too technical to call it an article on how to write good content. What you write is all fine, but how to use that information to write great content?
How do you translate "When writing text for a site you should always have keyword repetition and
Latent Semantic Indexing (LSI) in mind." into something something to use when writing?
I've struggled with this same problem a couple of years ago and realized that knowing and understanding all the technical stuff that search engines use is of absolutely no use when writing. I needed something useful that would help writing (structuring) content in such a way that all those technical requirements are met naturally.
And all those technologies that search engines use have, in the end, only one purpose: To understand the content of a page. So they look at the same things we, humans, do when reading something. We don't realize we´re doing it, but we look at paragraphs, structure, repetitions, etc. etc. etc. We use our current knowledge (memory) to understand what we´re reading (a form of LSI) and things like that.
We, humans, also do something interesting that's often forgotten. We teach our kids how to write a good text. Those basic lessons we had many years ago, are the key to writing and structuring the content we write today. Most of us have forgotten completely about it, and we just start typing until we´re done. There's heads nor tail to be found in what we write and often we start with subject X and end with subject Y and we don't even realize it.
So to have something basic to use as a guide to write good content, go back (in your memory

) to the old days and write the way you were tought. Here's a great refresher that I always use as an example:
Structure of the Five Paragraph Essay
The 5 paragraph essay is simple and helps you structure a text the way that search engine love. Once you've got that down to an art, you can get creative and go more advanced. As long as you keep the simple logic of the 5 paragraph essay in mind, you'll always write well structured content. Structure is the key to good content. After that it's creativity. But even a lousy story still sounds good if you use the right structure.