How to Create a Milky Way
1. Make a new document, any size doesn't matter. Press Ctrl+D to reset your palette colors. Set your background to black.
2. Apply Filter > Artistic > Plastic Wrap with these settings:
3. Apply Filter > Distort > Wave with these settings:
4. Apply Filter > Distort > Diffuse Glow with these following settings:
5. Press Ctrl+U and apply these Hue settings:
6. Now we got something like this:
7. I added a twirl to my final effect. Filter > Distort > Twirl: