Protection is paramount when you're on the move with your MacBook. I use both a leather folio and a sleeve. The folio is perfect for a day at the café, housing not just the MacBook but also pens, notepad, and charger. For travels involving a backpack, I slip my MacBook into a leather sleeve to guard against scuffs from zippers. Various options exist to suit different budgets, and you can find a quality sleeve on Amazon for about $30.