Water drop photography is very technical and need micro seconds precision to get repeated results.
The key is to have at least two back to back drops, timed so that when the first drop bounces, the second one hits and create the splash. Just when it is splashed, you take the photo. It's almost impossible to do it manually.
I have developed a diy using Arduino that controls two relays and camera. I have also developed a mobile application to define the size of drops, delays between drops and timing for triggering the camera. You also use flash to freeze the action.
It is amazing experience when you complete the project. Hope you like it. 🖐🏼