Step 1: Create a new document and fill it with black. We used 350px x 350px as the dimensions.
Step 2: Create a new layer, name it “Small” and fill it with black. Go to filter > noise > add noise then enter the following settings:
Step 3: Go to image > adjustments > brightness / contrast. Set brightnest at -30 and contrast at 75.
Step 4: Duplicate the “small” layer and name it “big”. Go to image > adjustments > brightness / contrast. Set brightnest at -100 and contrast at 50.
Step 5: Press Ctrl + T to open free transform. Hold shift and drag to make the “big” layer about twice the size of the “small” layer.
Step 6: Press Ctrl + I to invert the “big” layer. Press Ctrl + L to open levels. Enter the following settings:
Step 7: Press Ctrl + I to invert it back to normal. Press Ctrl + T and scale the “big” layer back down so that it is only slightly larger than the “small” layer. Change the layer mode of the “large” layer to screen. Now go to edit > transform > flip vertical.
Step 8: Take the eraser tool, use any brush that is not blury, set it to about 20px and start erasing pieces of each layer randomly. It should look something like this when you’re done:
Step 9: Flatten the document. Grab the clone stamp tool, get a crisp brush, set the mode to screen and start cloning until you’ve got the basic shape of your starscape:
Step 10: Duplicate the layer and name it “glow”. Go to filter > blur > gaussian blur and enter a radius of 7. Click Ok then change the mode of the “glow” layer to linear dodge. Now go to image > adjustments > color balance and play with the colors until you get a color that you want for your glow. We used 0, 0, +80.
Step 11: Create a new layer, fill it with black and set the layer mode to linear dodge. Go to filter > render > lens flare. Duplicate and resize this layer as many times as you want. If you lens flares are not the right color, merge the layers that have lens flares and hit ctrl + u, check the colorize box and play with it until you get the right color.
Now you have a beautiful starscape.