This page from the user’s manual for a tablet computer used in healthcare environments discusses how to use the barcode scanner.

Note that the writer uses a gerund (-ing phrase) in the major heading to describe the action (“Using the barcode scanner”).

The writer explains why readers might want to scan barcodes.

The writer lists the types of barcodes the tablet can scan and then explains how to enable the tablet to scan additional types. Note that the more conceptual information about the task precedes the instructional information. Why? Because readers want to understand the big picture before getting into the details.

The writer presents the steps. Note that the writer numbers the steps and uses the imperative mood for each one.

The drawing helps readers understand how to hold the tablet and aim it at the barcode. In cases such as this, simple drawings work better than photographs because they do not distract readers with unnecessary detail.