Be realistic about what your child needs to carry and shop accordingly. If they are likely to be loaded down with books, stationery, trainers etc, it really is worth spending more on a strong bag with adjustable straps that will spread the weight evenly
across their backs. Functionality is key - don't be tempted by logos or those emblazoned with characters from High School Musical et al! Dedicate some time to examining the bag: does it have enough compartments? These will help organize your child: if they know which school equipment to put where they are less likely to lose things. This will also help give them confidence, if they go to school assured
that they have everything they need and can get to it without fuss.
Backpacks are generally the best choice, unless your child does not have very much they need to carry - shoulder bags can be too heavy and are less likely to have those handy compartments. Dark colors are best for durability - most children will at some point drag their bag (even a backpack) and toss it in the corner of the playground, so
opting for a light/pastel colored bag will result in you having to replace it before the term is up.