"By valuable content, I don't mean simply writing about things that
people find interesting or useful- your content must also be considered
more valuable than what most other blogs in your niche are providing."
"In practical terms, targeting the long tail is about adding descriptive
words to your content. If you're targeting widgets, you already know
you want to work the word widgets into your content. But have you
thought about making sure you are adding words to describe things like
size, color and price or actions like buy, review and sample? Good SEO
writing is no longer just about creatively and subtly working keywords
into your content. Now it's about targeting the long tail by adding
less-searched for, yet still important qualifiers to your content."
Also, here are some useful reads from the HubSpot blog archives: