How to make water drops on a glass…
Open the picture you want to add the water drops top, I have selected this one
One your image is open, create a new layer(Shift+Ctrl+N) and name it droplets and fill it with black using the paint bucket tool(G).
Now the fun part starts, select Filter =>
Render => Fibres
and use the settings below.
Select Filter => Texture => Stained Glass and apply the settings below.
Just one more filter needs to be applied, use the settings below.
Now select the Magic Wand Tool(W) and make sure the foreground is black, tolerance is set at 32 and contiguous is checked. Once selected, click on the black area on the droplets layer. This will select all the black and leave the droplets. now delete the selected by pressing the delete key on you keyboard.
Deselect by pressing Ctrl+D and set the droplets layer to overlay and the opacity to 75%, you should have something like this…
The last thing we do is add a Layer Mask and select the Brush Tool(B), again, make sure the foreground is black. With the appropriate brush size, erase the unwanted droplets.