10 Useful WordPress Coding Techniques
www.smashingmagazine.com/2009/10/10-useful-wordpress-hacks-for-advanced-themes
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
In this article, we have compiled 10 useful WordPress code snippets, hacks and tips to help you create a WordPress theme that stands out from the crowd.