How to create your own trackpad gestures on a Mac

1. Create a gesture

Select Global on the left and click Add New Gesture. In the Touchpad Gesture pop-up, expand Five And More Finger Gestures and select 5 Finger Swipe Left.

In Predefined Action, choose Maximise Window left (in Window Resize & Move).

2. Test your gesture

Switch to Finder and open a new window, then perform your gesture. The window should immediately snap to the left half of the display. (Note: some apps have minimum window widths, which may take up more than half of small displays.)

3. Practise gestures

If you find it hard to consistently trigger a gesture, click Show Live View (bottom-left). The new window shows the positions of your fingers on the trackpad. Perform gestures and it'll state what action they would have triggered.