Packing a PackBy far the most often asked question I get is "How should I pack my backpack". Since I have already answered this question many times for individuals, I thought I would just write it all down and so everyone could hear about it.
The method used in packing your pack depends on what type of backpack you are using. An external frame pack sits the weight differently on your back than an internal frame pack. For externals, you want the weight to sit low. This helps balance you better as you are hiking. Internal frame packs are made to hug the body more. For this reason, you want to place the heaviest items in an internal frame pack close to the middle of your back next to your body. This helps keep the weight close to your center of gravity. When most of the weight is near your center of gravity, you will be able to turn around easier without the momentum of your pack whipping you down.
Your next question is probably "But what about my tent and sleeping bag". These are probably the next two bulkiest items in your gear list. Sleeping bags are great if you put them in a compression bag. This is basically a stuff sack with straps on the side to cinch down the size. This reduced size can easily be packed in the bottom of an internal frame pack. Often with externals, the sleeping bag is lashed to the frame on the bottom of the pack. External frame packs generally have less room in enclosed compartments then internal frame packs so most people tie larger items on the outside. When packing your tent, you might think about splitting up the tent into parts: tent body, poles and rain fly. This way you can spread the weight out across a few people in your group. The poles can be tied to the outside of a pack pretty easily. The tent body and tent fly can be stuffed into the top of your pack. The main reason for this is that the tent body and rain fly have a coating of waterproofing on them. When you fold a tent the same way over and over, this waterproofing can crack along the creases. By stuffing the tent and fly, they are never folded the same way twice and creases do not form. Another reason for putting your tent near the top of your pack is for easy access. The first thing most people do when they get into camp is put up the tent. With the tent being at the top of your pack, you save time from having to unload the rest of your pack just to get to the tent. This may not seem like much of a time saver, but if it is raining, having the tent near the top of your pack is a Godsend.
Clothes and smaller items are great to just stuff anywhere in your pack. Since camping gear tends to be in shapes that don't fit very well into a pack, there often is a lot of open space left in your pack. For internal frame packs, if you put your sleeping bag at the bottom of your pack, the bottoms corners of the pack are usually empty. These are great places to stuff items like camp shoes, socks or anything else that can fit in there. A good idea is to place all your clothes in a stuff sack. Not only does this help organize your gear, but it also provides one extra layer in case your pack gets wet. The rain fly is a great item to stuff into open space in your pack.
A few more things to consider when packing are your raingear, water bottles and lunch. It is a good idea to keep your raingear in a place that is easy to get to. This can be in the top of your pack or in a pocket. When it starts to rain, you don't want to have to dig deep into your pack to grab your jacket. Water bottles should also be kept very handy. Many packs now come with "holsters" to hold water bottles on the hip belt. If your pack doesn't have one of these, an external pocket is a great place to put a bottle. If you are hiking with a partner, a pocket out of your reach can still be used. When you stop, your partner can grab your water bottle for you. You don't necessarily have to put your lunch in an external pocket or at the very top of your pack, but it should be pretty close. Most people take a sit down lunch while hiking, so your pack will not be on your back. This allows for you to dig into your pack a little for your lunch.
Last, but certainly not least, keep the toilet paper where you can get it in a hurry. That is one item that you do not want to have to dig around your pack for. When nature calls, your TP better be within reach.
These were just a few things to think about when packing your backpack. Everyone creates his or her own style of packing after doing it a few times. Pretty soon it will just become a routine and you won't even have to think about it.