Problem: a wood bathroom door rubs slightly on the tile of a bathroom floor at the midpoint in its swing, sticking in place. I wanted to sand off the tiniest bit so that it swings free. But it wasn’t worth removing the door from its hinges.
Solution: get some rough sandpaper (I used 60 grit) and an old magazine. Open a dozen pages of the magazine and lay the sandpaper on top, grit up. (Without the magazine padding I’d be nervous that I’d mar the tile floor). Put this stack at a point in the door’s arc where it swings freely.
Before you start sanding: you want to avoid pulling off any strips from a veneer that may be covering the door’s surface. To avoid that, first sand the trailing edge of the door (that is, the side that hits last when you’re slamming it into the sandpaper), so it isn’t caught and pulled while you slam. Also consider using a finer grit of sandpaper, which would add a few minutes to the sanding, and opening-and-closing on the sandpaper with less force. Keep an eye on the veneer throughout the process.
Now, slam the door into the paper stack so that it sticks. In the process, it sands exactly the lowest point on the bottom of the door. Keep swinging it back and forth, slamming it into the sandpaper. As you make progress in shaving the door, you may need to add pages to the stack or move it closer to the point where the door sticks.
Test periodically. In a few minutes you’ve removed a millimeter or two from the bottom of the door and it should swing freely, without altering the look of the door or needing to remove it.
Besides the convenience of this solution, I enjoy its elegance: by replicating the act of making contact with the floor it shaves the door in precisely the right place.