What do you need your backpack for?
What are the most demanding needs of your new backpack? What matters most? Does it have to be multifunctional for work and play? Does it have to protect your electronics from rain and other elements? Most backpacks don't do it all, so be sure to choose one that targets your most specific needs and you will be off to a good start.
Shape and Structure
We have said this before; your backpack shape should generally match the contents of your bag. Hence, briefcases are good for square objects like folders, books and computers, while hiking packs are round and less structured for clothes. Structure also affects access to the interior compartment. Some backpacks are top entry, so you can easily pull items without unpacking the whole bag and some are front access, which are best laid down to pack for travel.
Internal Vs. External Pockets
External pockets are great for grabbing things on the run; small items that you want to keep separate so they don't get lost in the depths of your bag. Internal pockets are generally used as dividers and not as useful for quick grabs. Generally, the higher the pocket sits in the bag, the more useful it is.
Avoid at All Costs:
Poor Construction & Weak Materials
Backpacks get used and abused more than any other type of bag. Be sure to read buyer reviews from people who have used that bag or brand for an extended period of time to find any hidden flaws that may pop up down the road.
Lots of Straps & Compartments:
Keep straps and compartments to a minimum. What could be worse than having a huge bag that can’t fit an item larger than a helmet because the compartments are so small? Nothing, we say. Nothing.
Never sacrifice style for utility. Buy a bag that has them both; that's our motto.