First, it should be noted that not all stories are “User Stories”. For example a developer might be tasked with manually running some script. The Story might simply be “run the fooberry script”.

For everything that effects the UI, use a template:

As a < type of user >
I want < to perform some task >
So that < I can achieve some goal >

Note that it’s all about what the user wants. This isn’t about instructing what change to make to a system. It’s about advising implementers on what the desires of the user are.