Not sure if you have this but This is how the uv map looks if you want to be able to place things easier.
That might be wrong. I made like 50 billion different variations and can't remember what I stopped at.
I made the wrinkles in such a trash way tbh xD.
I went to websites looking for wrinkles in different fabrics, and then fused/mixed them together. I then ran software called crazy bump that generates normal maps based on lights and darks to get the design I was looking for.
Website used:
https://www.textures.com/category/wrinkles/112397
Software used:
https://www.crazybump.com/
Now a days what I would do is manually draw it on a high level model in zbrush and then render that as a normal and slap it onto a lower polly model.
Also just a heads up another thing I would do is set some of that stuff as a brush. It makes it easier to draw in photoshop:
That is what I do for my art when i want to draw realistic looking pampers.
I am not using Photoshop so brushes will be slightly different but you should be able to do the same thing in photoshop.
Finally for the clouds those can easily be recreated by overlaying circles.