The photo technique for capturing a high speed splash is not difficult once you understand the basic setup. When taking pictures of water, or glass for that matter, you need to begin by lighting the subject from behind. Since transparent liquids and glass allow you to see the background, this is the surface you need to light first. If your subject is highly transparent, like water, the background may be all you need to light. Otherwise you can add two more lights, one pointing directly at the subject from behind, and the other aimed at the subject from the front.
The key to freezing high speed action is having a light that gives off a very short duration of flash. Most flash units made for SLR cameras fall into this category. The flash duration is even shorter when the flash unit is used at a lower power rating, such as 1/16th or 1/8th power. The trade off here is in depth of field. In order to keep the splash in full focus you will need to stop the lens down to a low aperture, such as f/11 or f/16.
A light meter that can measure light from a flash is helpful, but not absolutely necessary. You can probably come close enough to the correct exposure with some trial and error tests.
Setting up the camera:
Your camera may have trouble focusing on the splash so set it to manual focus and, with the camera on a tripod, take a manual focus reading of an object placed in the spot where the splash will occur. Put the camera in its manual exposure setting and choose the highest shutter speed you can for your camera/flash combination. This is usually in the range of 1/250th of a second. A lens of medium focal length is a good choice. The ISO setting should be set low to maximize quality.
The exposure on the background should be approximately 1-2 stops brighter than the light falling on the subject from the front. With the camera set to the correct exposure for the subject, the background will now be pure white.