2. Get closer to a small subject to blur the background or to create “tama-bokeh”
The second point is to make use of blur. When you put the focus on LEDs, the source of lights, they become dots in picture. But when you shift the focus point, they are depicted as a blur of round objects. The further from LEDs the focus point is, the blurrier they get. And the blur of round objects, or tama-bokeh, gets bigger.
Compare two pictures below. In the top image we focused iPhone on LEDs in the back. In the bottom image we focused it on the Christmas tree in front. You can see that although their compositions are the same, the blur changes a lot depending on where the focus point is.
In general, smartphones’ cameras are not good at blurring. The size of the sensor is tiny, making the focal distance shorter. That said, they can still create some blurs. To make lights blurred, you need to find and focus your smartphone on something in front of them.
Any subjects that match lights are fine such as small flowers, signs, emblems of cars, benches and the like. If you can’t find such things, use instead your hand or accessories such as watch.