Sort through the items you need to put in your messenger bag. Stack the heaviest items in one pile and the lighter items next to it; keep writing utensils, money and electronics to the side for last.
Open your messenger bag. Place your heaviest items -- textbooks, your laptop, etc. -- in the back pocket of the bag. This places the heavy items against your body when you carry your bag, allowing it to rest on you instead of tipping over.
Place the lighter items next in the front pocket. If you have any loose papers, place them into folders to ensure they won't be torn and so you won't risk paper cuts when you reach into the back.
Pack your pens and coin bag in one of the small front pockets. In another front pocket, place your electronics, such as your phone, MP3 player or PDA. Make sure these front pockets are secured tightly, as they are the ones farthest from your body and could be inviting for pickpockets.
