How to take photo of a raindrop?
Raindrop can be photographed in different ways. It depends on the viewpoint of the photographer. Suppose you want to photograph of a raindrop ready to drip from the leaf of a plant then you need to get closer to the raindrop. Make sure that you frame the picture in such a way that it gives a pleasant look to the viewer. You can make use of the macro mode in your camera, if it supports that.
If you are using a DSLR then you can use a macro lens to capture the same. When you view through the LCD display of your camera or through the viewfinder you can actually see the inverted reflection of the objects in the background when you use the macro mode/macro lens. You can position some object like flower at this distant and photograph it to make it look more beautiful.
If your idea is to freeze moving raindrops on a rainy day then the trick is to increase the shutter speed of your camera. You can go for the semi-automatic modes available in your camera like the shutter priority mode where you have the option to select the shutter speed. Here you can set a higher shutter speed in the range of 1/500th of a second to 1/1000th of a second depending on the lighting condition and freeze the falling raindrops.
If you want to bring out some motion blur effect with the falling raindrops then you need to select a slower shutter speed using the same semi-automatic mode mentioned earlier. Choose a shutter speed of the order of 1/30th of a second to 1/100th of a second if you are shooting handheld (as shown in the above image). Slower shutter speed selection has resulted in a blurry effect in the picture shown above. If you are using a tripod then you can choose a shutter speed lesser than 1/30th of a second and bring more motion effect of the raindrops to the picture.