In one sentence, describe what the following article is about:

Packing properly will allow the chest and waist straps to bear more of the load, and for the weight to sit on top of your shoulders, rather than pull straps down into them. It will also make it easier to turn and keep your feet as maneuverable as possible. Keep the weight toward the back of the pack, resting against your frame. Some rucksacks have openings on the bottom that allow you to unzip and remove items quickly and easily from the base of the sack. These big backcountry-style rucksacks can hold a tremendous amount of weight, meaning that you'll need to play with weight distribution a little more carefully than with a smaller pack that sits higher on your frame. Set your rucksack upright while you pack the bag and keep weight dispersed over both sides evenly. Follow the same pattern with other items as they are placed in each compartment, taking care to balance the weight from left to right. Doing so helps to reduce fatigue and stress by distributing the load evenly between the shoulders. If you have an internal frame or frameless rucksack, place the flattest items against the panel that lies against your back. Avoid placing soft or bulky items here, since they can deform the shape of the bag, reducing the structural integrity. When you're hoofing around, this can cause uncomfortable bumps or protrusions that will irritate your back. Pack your clothes last, unless they make up the most substantial amount of material in your bag. Clothes are the easiest items to use as gap-fillers and jam into the remaining cracks. Plus, you can always get away with having one less pair of gym shorts in an emergency. Roll clothing tightly rather than folding it. This will allow the clothes to take up less room while also reducing wrinkles from crushing. Make sure that only enough clothing for the excursion is taken along, as this will help to preserve room for other essentials. This is especially important if hiking or biking for long distances. Opinions vary on how much weight is considered reasonable, although most rucksacks should be less than half of your total body weight at the maximum. As a last resort, it's common to have some important items easily accessible by hanging them off the rucksack from carabiners. This helps to maximize the holding volume of the bag by hooking things onto it, as well as allowing you to quickly grab a hold of a bottle of water, your keys, a knife, or other essentials. Most rucksacks are equipped with straps along the bottom that make it possible to secure bedrolls vertically, helping to distribute the weight and save space, as well. After everything has been packed, check to ensure that the pack sits comfortably and that you can access items without removing it when necessary. Always wear it for ten minutes minimum and walk around testing the feel of it, mimicking what you will do when wearing your rucksack. Pay attention to where you feel the pressure of the straps, and whether or not the bag is throwing off your balance as you move. If so, you may need to reposition some of the items in the bag to distribute the weight more evenly. Casual backpack wearers such as students often leave the straps loose and let the rucksack sag low over the rear. Wearing a heavy rucksack loose and low would be miserable on a long trip, so it's important to keep the straps tight and the bag as high on your frame as possible.

Summary:
Pack heavy objects in the middle and toward the back. Balance the weight evenly on both sides of the pack. Keep the back of the rucksack relatively flat. Use clothes to fill space. Keep the overall weight of the rucksack under a reasonable limit. Get some carabiners. Test it out and check the weight.