Sometimes you can forgot a polarizer filter or simply you don't have it. If you have photoshop, you can do beautiful sky difrent methods. I would like show one of them today.
You put picture in photoshop and make copy of this layer. Select this copy layer a select in menu "Apply image".
Channel = Blue
Blending = Vivid Light
and on the end we check off Invert.
Now we select this adjust layer and set Overlay between 20-50%. We can use Filter - Reduce noise, if we need.
Done, that's all. Mayby this will be useful somebody.