You get ONE backpack. ONE! That's it!!! No roller bags, suitcases, giant duffle bags...just one carry-on sized backpack. How large is carry-on? I recommend a backpack no larger than 50 liters in capacity. I have one traveler's backpack that I take everywhere. It's 50 liters and has compartments that can easily fit 10 days worth of clothing. Perfect for hiking and excessive walking. I strongly recommend the Osprey Stratos 50 backpack. It runs quite pricey at 150-180 USD but I promise it is a worthy invenstment when it comes to compact travel. It breathes with you and reduces sweat during walks and hikes. It has back supports and fits into almost all overhead compartments. There was only ONE instance I when I was asked to check it. It was at New Haven's Tweed airport. A tiny airport for pocket sized aircrafts. In this situation I used my 30 USD Osprey Airporter to protect my Stratos 50 while in transit. If you're going to purchase a backpack I recommend getting the Airporter to go with it. Airlines insure what's in your bag - not the bag itself. Though I could check my backpack by itself, if it were to get lost or damaged, I could not be compensated by the airline. But if my backpack is inside another bag, it's considered insurable property. The Airporter provides a convenient work around for this. The airporter is small enough to roll up inside my Stratos 50.
But flights like these are rare. On common commercial flights you'll be safe and no one will ask you to check it.
2) Only 1!
1 pants. 1 shorts. 1 shoes. 1 jacket. There is no need to pack more than one of these things. You can wear these items more than once. This way you can pack the rest of your bag with undies, t-shirts, and socks according to the number of travel days (usually no more than 10 shirts socks and undies). Laundry is global! Don't forget that if you need to wash your clothes, hotels, hostels and most towns have laundry services. I haven't ever been in a situation where laundry was inaccessible. Simplifying can difficult but it takes practice. There comes a cathartic feeling when you add able to travel minimalistically - only bringing what you need. It really amplifies the sense of freedom, mobility, and flexibility. I want you to experience this. True freedom of wanderlust and adventure. Do not lug yourself down with