You don't remember hosting a 'running of the bulls' event in your hallway, but there it is - a gored wall. You find yourself staring at an irregular hole marring an otherwise perfectly good wall.
Patching drywall is easier than it looks; you just need the right tools and a few basic principles.
1. Use a utility knife and or coping saw to square the edges of the drywall hole.
2. Cut a patch from a new piece of drywall, making sure it's slightly smaller than the squared hole. But, don't try to insert it into the hole without a solid backer in place to stop it from falling in behind your wall.
3. To form a backer, cut a piece of scrap wood or another piece of drywall that wider than the square hole. Wrap one or two lengths of wire around it. Insert it into the hole and lodge it against the back of your damaged wall by pulling the wire snug. This backer creates a new 'bottom' for the hole.
4. Secure the wire on your side of the wall so the backer remains in place, then insert your patch in the squared hole. Apply drywall compound around the edges of the patch, smoothing it flush to the undamaged wall.
5. Allow the compound to COMPLETELY dry, then snip the wire flush with the wall before sanding and painting.
You'll be good to go in under a day and no one will know about the out of control bulls in your hallway.