Size
A 40-50 litre pack is a good choice for a short trip. Bags this size should have enough capacity to fit in all your stuff but be small enough to carry comfortably. They should also compress easily to double as a larger daypack if needed, and be versatile enough for multi-day walking.Back length and 'systems'
Some bags are ‘one size fits all’; others come in different sizes, based on the length of your back. Try the pack on – with some items inside it – before you buy it to make sure it fits comfortably. Most packs have a ventilated back ‘system’. This is usually sculpted foam and mesh panels or a curved static frame that holds the pack away from your body so that air can circulate to prevent you getting sweaty while you’re wearing it.Shoulder straps & hip belts
The shoulder straps balance the pack; look for padded straps, for greater comfort. Try the pack on to make sure the straps don’t contour into your armpits too sharply, which can cause rubbing. The hip belt supports more than half the load so make sure it’s comfortable and fits well without restricting your natural movement.
Rucksack in the German Alps (Shutterstock)
Lid
Look for a generous pocket – handy for storing frequently needed items or wet garments. Some lids are stitched to the bag, others are ‘floating’ (held on with adjustable straps). The former help to stop rain getting into the main compartment, the latter enable you to more easily fill the pack to maximum capacity.Pockets
Every pack has a different configuration of pockets. Pockets can be useful for organising your stuff (especially in larger bags), though too many can get confusing. Most packs have an internal pouch at the back that is compatible with a water reservoir/bladder; if you don’t use the pouch for water, it can be handy for storing important documents or an iPad/tablet. Look for packs with bottom/side openings – these allow you to compartmentalise your clean/dirty clothes.Fit
Some packs are unisex, others come in specific women’s versions; these are cut with a female shape in mind – women carry weight differently to men due to muscle structure. Bear in mind that some men may find a women’s fit more suitable and vice versa.Wand pockets and compression straps
Designed to store your water bottle and keep your rucksack compact, these pockets and straps are also useful for stowing camera tripods or walking poles. Make sure they are large enough to accommodate your items.Main image: Man with a rucksack (Shutterstock)
