These out of focus highlights are actually called "circles of confusion", and result from points of light - like street lights, and string-lights being out of focus in an image. For clarity's sake (ironically enough) we'll just call these dots bokeh for this instructable.
It doesn't require any special equipment - just follow a few simple steps to create bokeh circles of your own.
Step 1: Look for Bright Dots
Step 2: Focus on Something Close
If your camera offers manual mode, just change to that setting and turn the ring until you're happy with the result.
Step 3: Change the Shape
Step 4: Open Your Aperture
Step 5: Learn More About Bokeh at Picture Like This
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