A trigger is basically a hot-key combination to perform one or more actions in QS.

1. Open QS preferences
2. Click on the Triggers menu
3. Click on the '+' button
4. Now type in just like you would if you were using QS
5. Tab through to select your desired action (you can press down to browse action results)
6. Save your Trigger, leaving the Trigger field blank
7. Now, on the far right of the new trigger's row should be the word 'none' next to an icon of a keyboard key
8. Double click 'none' and press some combination of keys simultaneously; this will become your trigger
9. Now whenever QS is running, you can press those same keys simultaneously to launch the preset action