6. Reset your foreground/background colors by pressing ‘D’.

7. Create a new layer (SHIFT+ALT+N) and go to filter>render>clouds.

8. Next go to select>color range. Move your fuzziness to 200 and select any white part of the clouds. Try to select an area where it is the whitest. This is what your selection should look like.

9. Hit the delete key to delete the selection and this is what you should be seeing.