Summarize this article in one sentence.
Lay every item you want to put into your bag across a flat surface. Then, from left to right, lay out your items from lightest to heaviest. Double check you have everything at this stage, because if you pack it all and forget something you may have to unpack everything again. Shoes offer lots of protection for items that can fit inside them. Store pairs of socks, underwear, or even rolled up shirts inside of shoes to keep them safe and to save space elsewhere. Put all spare shoes, sleeping bags, and general accessories that you won't access frequently at the bottom of the bag. Putting all the light clothing at the bottom of the bag means that they will be able to squish down once you put heavier clothing on top of them. If you are camping this is where you should store all essential supplies such as pots, pans, stoves, and camping gear as well as any precious electronics that you can't do without. You will be accessing this area of the bag at least once a day. By placing all these items in the middle of the bag, they are receiving the maximum amount of cushioning by the clothing at the bottom and the clothing that will be on top. You will be accessing the top of the bag frequently, so put anything here that you'll need on a daily basis. This could be hats, jackets, umbrellas, or extra layers depending on the situation. By putting these items at the top of the bag, you'll be able to protect yourself from the elements as soon as possible.

Summary:
Sort all your items by weight. Store as much as you can within the soles of shoes. Store all light items at the bottom of the bag. Put all heavy items like camping essentials in the center of the bag. Place all medium weight items at the top of the bag.