I know this is a pretty simple Tutorial but, it helps me a lot

OK

Make you BG black for a start
Then get your 192 Pixel Brush that looks like a Firework
Make your Foreground Colour white
Now Spread your brushes off in NW, NE, SW, SE
Now that that's done, go to
Filter>Blur>Motion Blur
Amount: 999%
Angle: about 27 Degrees

If you did it properly you should get something like this:
(This one was a Sig with Engravings i made for Ravon, but he never used it)



Post up your results if you wanna