For comfortable carrying of a day pack:<br><br>Put heavy (dense) items close to your back and high in the pack for better center-of-gravity.<br>Pack tightly so items don't shift around or rattle-- Compression straps can help here.<br>Try to keep the load flat as in "flat against your back" instead of having a thick, ball-shaped load.<br>You will want to avoid having anything hard or sharp poking into your back-- a thin layer of soft items like clothing inside the pack against your back can help.<br>Make sure you know how to properly adjust the straps and especially a hip-belt if you have one: there are many subtle adjustments that make a big difference.<br><br><br>For convenience:<br><br>Without violating the above, try to keep the most-needed or first-needed items near the top of the pack or in the most accessible places. Water will be one of the most-needed items and also the most dense, so think carefully about how you will pack that. Also remember that if your flashlight is buried in the bottom of the pack, you can't find it when you need it (in the dark). Have a spot for it where you can find it without searching. <br><br><br>Also think about items you might want to retrieve with minimal delay, such as a camera or first-aid kit. You don't want to paw through your entire load with a bleeding hand.<br><br>And remember to keep at least some survival gear out of your pack and on your person in case you get separated from your pack.