Create a new workflow and select WP Fusion as the trigger.
The available options are Tag Added to User and Tag Removed from User. For each you can select a single tag from the dropdown.
Then, connect your trigger to one or more actions.
When the selected tag is applied (or removed), the connected actions will be triggered.
WP Fusion can also be used as an action connected to another trigger. The available actions are Add Tag to User and Remove Tag from User.