If you look carefully at the photo above you will see that I am holding a rather strange door latch. This thing is called Door Tite and it solves so many problems with exterior doors such as where you have to pull hard part of the year to be able to close the deadbolt with your key. It has a little stair like catch that ratchets the door in tightly even if the door warps regularly with changes in the weather. I can't find these in stores any more but I am still looking for the manufacturer. Click here to see an animation of this little gadget in action.
As for inside doors, we often want a door to open or close by itself, or to stop doing that. Put a level on the hinges. If they are all perfectly vertical, one above the other, the door will stay wherever it happens to be. If the top hinge is not exactly vertically above the bottom hinge, the door will swing in the direction of the top hinge. So you can simply put toothpicks in the screw holes of the top hinge and then put the screws on the outside edge of the hole, and the door will tend to stay open. If you do the same thing to the bottom hinge, it will tend to stay closed.
When you are removing a door, always remove hinge pins from the bottom first, so that the door will not fall on your head before you are ready to handle it. Take off the top pin last. If possible, work with the door closed, and it won't go anywhere until you are ready to remove it.
How do you get a heavy door back on its hinges when you are alone? Slide the door on the floor up to the hinges. Pivot it up with the handle edge still on the floor. Get the bottom hinge to enter into its other half, more or less. Put the pin in place and then wiggle the door until the pin drops enough to grab the first two hinge knuckles. That is enough to keep it in place for the moment. Now that the bottom is under control, grab the handles with both hands and lift the door up. If the top hinge doesn't slide right into place, drop it back down to the floor and swing it up forcefully. If the alignment is close, it will force itself into place. Either slip the top pin into place quickly, or close the door so that it will hold itself in place while you try to find where you left that hinge pin. Now you should be able to tap the pins into place. I assume you remembered to freshly oil those pins while they were out.