There's no right way here, but different methods work better for different people. Most day packs offer access from the top in some way, whether its a roll top or a drawstring. Many top loading day packs have a lid for smaller items and an expandable sleeve that can fit extra gear. Panel loaders have zippers or other fasteners on the front of the pack to allow access all the way around. Mesh pockets offer easy access, but zippered pockets make sure nothing falls out on rough scrambles.