Advice on how to make this kind of background

[HenriR]

Hi everyone,
I would like to make something like this kind of background with my own colors.
I am not sure which technique I should look for.
Is this something to achieve with different brushes? are they smoke effects?

Is it better to start from a scratch or a stock image?
Anyone help so I could lead my research on the right way would be much appreciated.

Thanks a lot

[c.pfaffenbichler · Accepted solution]

If you want to be fast I would recommend Stock images, if you want to play around then the Noise and Clouds Filters are useful for creating some randomness (for the stars, also as a basis for the cloudy structure). 

[c.pfaffenbichler]

For the stars a white Layer set to a low opacity with the Blend Mode Dissolve can be useful.

Converted to a Smart Object (with Blend Mode Normal) one can scale it up to create stars of various sizes. 

[HenriR]

This looks amazing. Many thanks, I am definitely going to play around with it.

[PECourtejoie]

Hello, In addition to the stunning examples by C_Pfaffenbichler, before you purchase stock images of space, do check the thousands of free of right of NASA: https://www.jpl.nasa.gov/spaceimages/ or https://www.nasa.gov/multimedia/imagegallery/index.html 

[PECourtejoie]

There is also the ESA: https://www.esa.int/ESA_Multimedia/Images

or JAXA: http://jda.jaxa.jp/en/ but I did not check for their copyright status.