The main problem with the common camera owners is that they wait till dark and that is too late to start shooting. Because of this, they either have the lights or the surroundings properly exposed; but not both.
The best time to shoot the festival lights is before it gets totally dark, during the twilight hour. The time around sunset will give you time to plan your shot before the right light balance happens naturally.
Shoot from a low position to compose your photo to include as much sky as possible in the background. Use a tripod or a firm rest to steady your camera. Keep the exposure time in the range of a quarter second to a full second at twilight.
Shoot a test shot after every five minutes minute or so. Eventually you will get the festival light to come up properly as the ambient light level goes down. You will get the best shot when the ambient and artificial lights cross balance.