I’ll start with a neat water effect.
[list=1]
[]New Doument 700 x 700 white bg
[]Press "d" to reset colours
[]Filters >> Render >> Clouds
[]Filters >> Render >> Difference Clouds
[]Filters >> Blur >> Radial Blur
Quality Best, amount 20.
[]Filters >> Stylize >> Chrome
Both settings on 10
[]Image >> Adjustments >> Curves
Imagine the curves view as a graph (origin in bottom left) then you want a point on (3,1) and another on (2.3)
[]Image >> Adjustments >> Colour Balance
Cyan -80 and Blue +80
[/list]
Et voila. 
