Result:
Click here to view!

1. Create a new document. I will be using a document size of 800x600 which is one of the sizes of wallpapers, for this tutorial. Fill it with #000000, to a dull #27798B gradient:
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2. Now, make a new layer and keep the colors still as your back and foreground color and go to filter>Render>Clouds, ctrl>f 3 times or until you get something you like. Then set the blending mode of the layer to Soft Light. Now you should have something that looks like this:
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3. Looks good ey. Next press d then x and get the 'AirBrush soft Round 300' brush, create a new layer, and make a white dot in the bottom middle of the page.
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4. Next Create a new color adjustment layer (Layer > New Adjustment Layer > Color Balance), and set the settings as follows:
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5. Click ok when your done and then create a new layer under the adjustment layer but on top of the large white dot layer and select a large brush (300 px, round, 0% hardness) and make another dot on top of the first large dot that you created:
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6. Next select your smudge tool from the tool bar, set the pressure to 50%, and select the 'Oil Medium Wet Flow' brush (size 32 px). Start from the outside and drag inwards on your large dot from outside of the dot to the inside. This will take lots of clicking and dragging, once you think you've done a good job, start dragging in and out rapidly with the smudge tool:
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7. Next make a new layer( under the adjustments layer but on top of every other layer), get your brush tool and get a soft round 65 pixels brush and make a line across your image horizontally:
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8. Then press ctrl+T , then rotate the line diagonally and move it like so in the below screen shot:
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9. Now its starting to come along. Now go back to your large white dot layer that we were smudging before and start smudging it up using the same steps as before and start smudging it from the middle of the dot, start dragging upwards so it begins to merge with the beam:
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10. Now you have to get some stary brushes that can be downloaded here:
http://www.deviantart.com/download/5385645/

After you have uploaded the brushes, make a new layer ( under the adjustments layer but on top of every other layer), and start brushing up the places near the beam, brush up around the beam and try to get something like this:
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This concludes our tutorial, you should have something similar to this:
Click here to view!