Create a new document. Using the soft brush with the Spacing set to 14%, hold shift and drag the brush downwards to create a straight line on this new layer.
Put a 50-pixel Gaussian blur on it and use the Eraser tool to rub out some of the ends of the line. Go Cmd/Ctrl + Shift + T and rotate by 45º. Alt + click the layer and flip horizontal to make an X shape with the lines.
Merge the two selected layers (Cmd/Ctrl + E) and transform it (Cmd/Ctrl + T) to make it smaller. Place this shape on the canvas near a light burst, and Alt + drag and transform a few smaller ones, place these around the composition too.