In the world of smart backpack, you'll hear things like top loaders and clamps and suitcase unzips.
The top loader is a bag that can only be entered from the top.I've been traveling with this bag for years. I pack lightly, so my upper loader bag never bothers me. But my last two bags opened like clamps and were pulled open like suitcases, and I loved it. It was very satisfying the way the backpack kept its shape, even if it was empty. When it's full, I can easily decompress and see everything in the bag at a glance.
If you follow my advice, please keep it small. Compartments are not a problem for you.
Once you start carrying more gear, it's great to have a way to separate them. Many bags come with a "shoe" compartment, which is essentially a waterproof compartment in the bag.In most cases, this is a good place to store dirty shoes.But on a rafting trip, for example, you have no choice but to bring all your gear, and you can keep items like your passport and electronic devices that may be doubly protected in this compartment.
I want my suitcase to have at least three parts: a main compartment, an auxiliary compartment, where I tend to put all my little gear in the packing list, and a front compartment where I store my boarding pass or items sometimes for specific categories of things.
Being able to move things quickly into your bag is very important to me. However, as I will explain in the "Security" section...If you can get something out quickly, a thief might be able to do the same. I like to have a travel toiletry bag on the top of the bag, unless you already know, you can't even see it.
Think about what types of pockets there are, how many pockets there are, and how they open. How do you get what you need out easily? Water bottles as they ride through Thai cities in a tuk tuk. When you sit on a 12-hour flight, sit in the middle seat with a book or tablet. Try to find the phone number for hotel reservations. When it's dark on an overnight bus in Argentina, your earplugs and sleep mask.