My second lifehack tip is for storing receipts while traveling on business. My solution is the Moleskine Memo Pocket book. Unlike the other Moleskin's, which you can actually write in, this tiny book only has pockets (six, actually.)
At the end of each day I put all of my receipts into a pocket in the Moleskine. If I'm traveling for under a week, I use a different pocket per-day. For heavier traveling, I use one pocket per-week, or per-city. And even though the book is small, you can jam a whole lot of paper in there and still close it!