For many people, it can be pretty difficult to create an updater-script. Thankfully, there are some tools that can help out with basic commands such as a GUI-based utility by XDA Forum Member Octanium91 called Android Script Creator that allows you to create an updater-script with just a few clicks.
Android Script Creator does all the dirty work for you. All you need to do is select which option should be added to your current updater-script. Every option is presented through a simple dropdown menu that explains all of the commands. The generated script can then be used with a ROM, application, mod, or practically anything that can be flashed through a custom recovery.
If you would like to check this out yourself, head over to the Android Script Creator Tools thread for more information.