This tutorial will teach you how to make a basic water effect.

1. First make a new image any size you want.

2. Then Scribble with your favorite brush (fill up most of it).

3. Then do Filter > Render > Difference Clouds.

4. Then Filter > Artistic > Neon Glow make it light blue and 33 brightness and 24 glow size.

5. Filter > Distort > Wave

6. Filter > Distort > ZigZag:

Amount: 33
Ridges:18

7. Filter > Distort > Glass

8. Filter > Distort > Ocean Ripple

9. Scribble on it

10. Then Filter > Render > Difference Clouds

11. Then Filter > Render > Difference Clouds

12. Then Neon Glow and change the scribbles to the same color as the background.

13. Filter > Distort > Wave

14. Image > Adjustments > Hue/Saturation

15. Change it to whatever color you want.

Here is the final result.