A useful daily backpack should match what you actually carry rather than simply offering the largest capacity. Consider laptop size, documents, chargers, water bottles and the amount of walking involved in a normal day.
Capacity and organisation
Multiple compartments can help separate electronics from smaller accessories. Too many small pockets, however, can reduce usable space, so choose an arrangement that matches your routine.
Comfort
Padded adjustable shoulder straps and a stable back panel can improve comfort. Avoid routinely overloading a bag beyond what is comfortable to carry.
Materials and zips
Inspect material, stitching and closures when durability matters. Water resistance is different from waterproofing, so confirm the specification if protection from heavy rain is essential.