One of the things the GW Study Abroad office will stress before you begin your journey is that you should travel light. Pack only what you need, and make sure that the items you bring with you don't exceed two suitcases. The Study Abroad office also recommends bringing a small, empty duffle bag with you to transport any purchases you may make while abroad back home. Go for a simple cloth duffle that you can roll up and stick in your suitcase.
The question is, in terms of souvenirs and remembrances, how many should you buy? Obviously you want a souvenir from every major country or city that you visit, but you don't want to clutter your small abroad room or exceed your baggage limit on a plane. How can you purchase all of the remembrances from your trip that you desire without going over the limit - and without breaking the bank?
My trick? Postcards. For awhile now, I've collected postcards from all of the places that I've visited. They're cheap, lightweight, and you can write fun anecdotes on the back about where you were and who you were with. I date each postcard I buy and write the exact location I bought it on the back so that I'll always remember the details of my trip. Are postcards not your thing? Then find something small that you love! Maybe you'll try to find a magnet or keychain from every city you visit. Who knows? But find something small and inexpensive to help you remember your trip.
Obviously there will be one or two larger souvenirs you just have to have. Maybe it will be a native scarf or dress from the country you're visiting. Maybe you'll fall in love with a hand-carved figurine. Maybe you just love the chocolate and you want to bring it home for your friends and family to try. It's okay to buy a few big-ticket items, but make sure you really want them. Don't buy things impulsively! Save the room in your suitcases for the purchases that you fell in love with, and use small items like postcards to simply remember your trip!