Step 1
You should already have the brushing finished. Now, we're going to change the background a little bit. Make a new layer and place it under all of the other layers. Make sure you delete the old black background so it doesn't cover this up. Goto your gradient tool and set it to radial. Choose a DARK blue foreground color and set your background color to black. Starting from the left of the canvas, click and drag all the way to the right. Your background should now exhibit a dark bluish tint.
Step 2
Now get your abstract image and place it in the middle of your clouds. Pick a blending mode that looks nice. I chose Luminosity.
Step 3
Create a new layer and select your Brush Tool. Select a soft small brush and set the flow to 50%. Draw a straight white line. Now goto Filter>>Distort>>Shear. Apply the settings as shown on the picture.
Step 4
You should now have a wavy line. Press Ctrl+T and transform it so it is running horizontally and not vertically. place this line so it looks as if it is coming out of the center toward the edge of the screen. Duplicate this wavy line 3 times and put them close to each other. Rotate each line until they vary slightly enough so you can see them individually. Do this as many times as you like to make tentacles. Now apply an Outer Glow on all of the lines. Set the color to white and Opacity to 100%.
Step 5
Now apply some "Fairy Dust" on the tentacles. Reffer to my other tutorial located in effects to find out how to make the dust.
Final Result:
