Debugging Techniques
Introduction
These techniques should help you to find bugs faster when you're scripting.
Hints
If something is not working, check which variables could be wrong, check the output of the variables using hints.
Vektorboson released a 'debugging console for advanced users that is very helpful at debugging your scripting in real time.
Documentation on using the console can be found http://home.arcor.de/vektorboson/res/console2.0docs.zip here).
If you're at an advanced stage of a project, you can save the game when the bug appears and check the variable and script states with Chain of Command's Binary gamefile viewer.
Keep it simple
If your having great difficulty solving a problem, simplify the problem, take the part of the mission which does not work paste it into a new test mission, so that you don't have to watch/whatever the effect of the whole rest of the script(s).
Addon Tips
If you're scripting for an addon, don't pack the scripts in the PBO, as you have to restart after every change, make a test mission with the script included there.