Clouds, Particle or maybe prefab?

Hi forum, I am trying to add some fog/clouds effects, to a sidescrolling 2D Space game. I tried some various cloud prefabs, but it seems that when using these particle generating systems, it creates a random setup each time, not always good. How or more like, what would I need to make some clouds (Stationary, but transparent as it is seen from above the clouds down through), but not having it random generate them each time I run the game?

Solving my own question for future referances, and other people. A way I found to do this, was to use a plane between camera and world, and using a transparent image of clouds, that I made using this tutorial:

The result ended looking like this: