Like anything else there are ways to do something and then there are the best ways to do something. I would never claim that any article best described the way you personally should pack your hiking bag. I understand this is as personal an endeavor to some as how they put on their underwear. That said we can get some great advice and guidelines from this article on how to pack a bag effectively. This article also offers a section about procuring the right bag as well. This is a very important step. Do you know what 40L means and how it affects your ability to pack for certain trips?
The article features sections on organizing gear and using inertia as your friend when packing and carrying heavy gear. This article is as much a safety article as it is an article on packing a backpack. Then again I guess the two are inextricably tied. On a side note, many of these tips can be applied to your bug out bag as well.