In order to pack your backpack correctly, you may want to lay out all of your backpacking equipment to get it organized. This is a great way to make sure you have all your gear and organize it by weight. Another good idea is to cluster similar small items, such as eating utensils and pots, together in zip lock or stuff bags. You may want to even go further and color-code them as well. It is also a good idea to store food and liquid fuel in bags to prevent spills.
When loading your pack, be sure to follow the weight distribution guidelines given above. As lightweight items should be stuffed at the bottom of the backpack first, the sleeping bag usually goes in first along with other light nighttime supplies. After, pack medium-weight items, followed by heavy gear.
When packing your backpack, be sure to fill in all empty space with small or compressible items. For example, you can stuff a shirt inside a pot, put a roll of duct tape around your hiking poles. If you are using a bear canister, as more and more national parks and wilderness areas are requiring, be sure to fill it completely full with food and other scented items (be sure to pack this closest to your back).
Certain items like a GPS, insect repellent, snack food, rainwear, or a headlamp may need to be accessed at any time. Because of this, these essential things should be stored inside a front pocket, top lid, or in the top of the main compartment so they can be found with minimum searching.
Your absolute “get to items” should be Rainwear, First Aid Kit, Compass, and Emergency Whistle.