Create Heavenly Clouds

The final pic
Create Heavenly Clouds

1. Start off by making a new document, 500 x 500 px or whatever you want, with transparent background. Press D to reset colours to black and white.
2. Go Filter > Render > Clouds, then Filter > Render > Difference Clouds 2-4 times.
3. Open up levels (Ctrl + L), and change Input Levels to something like 30, 1.00, 70. Press OK.

4. Set the layer's blending mode to screen, and also make a copy of the layer. (Both layers should have blending mode screen)
5. Create a new background layer. Make a linear gradient on it from top to bottom with #3B6EB2 to #6AB3F9. Looking like clouds already.

6. Select any of the two cloud layers. Go Filter > Stylize > Extrude with these settings:


7. On the same layer go Filter > Blur > Gaussian Blur with a radius of 3.5 px.
8. Now invert both layers (Ctrl + I, on each layer).
Here's what got another time, the result differs from time to time and I think this one's nice:

The final pic