Help get everyone in shot, including yourself, by using the Timer option. When using the Camera app tap the Timer icon at the top (it looks like a clock face) and choose between a 3-second or 10-second delay. Prop up the phone and press the take picture button.
The LED flash will illuminate to demonstrate the countdown. It then takes a burst of 11 shots to ensure you get the perfect one – you can then look through them to pick the best.