We've given you a lot of moving tips, but it doesn't get much simpler than this. Blogger Mike Figueroa realised he could cut out a lot of heavy box carrying by sliding them down a wooden plank.
Obviously, you wouldn't want to do this for anything fragile, but for those heavy boxes filled with, say, books, you can just make a simple ramp on the stairs and slide them down. Now if only there were something as simple for moving boxes back up stairs. Check out the video for a demonstration, and share your favourite moving tips in the comments.