Pockets A big front pockets is handy for stashing jackets, food, or whatever else needs to be easy to access. A top pocket is also another handy stash spot. Check the quality of the zips – they are a common weak spot. A flap over the zip will help to keep the pocket’s contents dry.
Bottle pockets that can be reached while walking are great for keeping hydrated, as is a bladder pouch.
Compression straps If your pack is not full, the load can move around, affecting your balance. Compression straps are designed to be cinched tight to keep your rucksack stable. They can also be used to attach things to your pack: for example, a mat or a tent on the bottom straps, or poles or skis on the side. Very strong stitching is needed for these straps, as is a good design so they are efficient in use.