During installation, the Philips Hue app illustrates a placement example for the type of room you select. In order to find the best placement, please open the Philips Hue app and select "Settings" > "Accessory setup" > select your sensor > "motion sensitivity". The App will then start the sensor test mode. The test mode allows you to instantly see feedback on whether the sensor detects you, by checking the LED indicator on the sensor and/or App screen.
The LED on the Hue motion sensor will light up when motion is detected, and turn off when there is no motion detected for more than 5 seconds.
The test mode will remain active until you exit the "motion sensitivity" screen.