Open the image you would like to add water drop.
Create a new Layer. Rename if you like. I’m renaming it as “droplet.”
Select your Elliptical Marquee Tool & press & hold Shift while dragging it to create a perfect circular selection.
Open your Gradient tool & click on the bar to open the Gradient Editor. Click on the 3rd thumbnail to select the black –to-white gradient. Then click Ok.
Go to the upper-left of the circle and press Shift as you drag diagonally down to the lower right. Pressing shift allows you to create a straight line.
This will create a gradient like the picture below.
Deselect the selection by pressing Ctrl + D.
Change the Blend Mode to Overlay.
Double click on the droplet layer to open the Layer Style window. Click Inner Shadow. Change the Blend Mode to Linear Burn, the Opacity to 40%, uncheck Global Light, and make the Angle: -30°, Distance: 2px, & the Size: 5px. Depending on the size & resolution your image, the distance & size may vary.
Now click on Drop Shadow. Make the Blend Mode: Linear Burn, the Opacity: 30%, uncheck Global Light, make the Angle: 127°, Distance: 8px & Size: 14px. Then click OK.
Now we’ll put a small highlight reflection on the drop. Click on the new Layer icon & create a New Layer. We’ll name it highlight.
Now make sure that the white is in the Foreground.
Select the Brush tool and go to the Brush setting. Adjust the brush size to a small size, in this case, I’ve adjusted to 4px. Depending on your water droplet size, this number may vary. Keep the hardness at 90%.
Press down once on the upper left of your water drop.
Now the water drop is done.
To create a copy:
Select both the layers (Shift + click) and place them in a folder by pressing Ctrl + G. Make a copy of it.
Drag the copy to another spot and resize it to your liking (if you want to). To resize the water droplet, press Ctrl + T to activate the Transform tool and press Shift + Mouse Down to make it bigger or smaller. By pressing Shift, you can retain the perfect circle shape.
The final image will look like this:
Check this out while you wait!