The best way to find the bugs and errors in a program is to hunt them down, either by yourself or in a group. How do you find a bug? Well that's the hard part, you don't know where and when a bug will occur, the only way to find out it to tinker with everything you can. Try doing things you normally don't do when executing commands. Here's an example:
Say Johnny is fighting two bats, so he clicks on one bat to start attacking. Then an idea forms in Johnny's head to click on the other bat while attacking the first one. Behold! The second bat is being attacked along with the first! That is a bug (and it may actually be one in game so try it out.)
Now, when you have found a bug, the best method to report it is to give a lightly detailed report on how you got the bug to occur. By doing that, you give me the opportunity to try and replicate it, and therefore find a way to trap and destroy it for good! Of course there are no real in-game rewards for finding bugs except helping shape and fix the game you are playing. That should be the greatest gift of all.
Thanks for reading, now go hunt down those bugs or they'll hunt down you!

