Simply wake your phone screen and hold the phone less than a centrimetre away from the contactless terminal with the phone screen facing up. Make sure your phone stays awake.
Hold the phone still over the terminal until the terminal beeps or your phone vibrates and/or beeps. If that doesn't work, try holding the phone sideways across the contactless terminal. Each phone has its own 'sweet spot' and this will become familiar with practice.
If you have a cover on your phone, you may need to remove it in order for your phone to communicate with the contactless terminal. Make sure there are no other contactless cards (credit cards, transport cards or building swipe cards) near the terminal as this may interfere with the payment. See our How to video for instructions.