I took a break from water drops, and did some milk photography. 

Is milk photography easier than water drops?  It depends.  Milk has it's own challenges.  I use a piece of glass for the milk to land on.  The problem is, glass reflects every piece of dust and swipe from the cloth.  I am tempted to take everything else out of the room, just so there will be less dust!  It is maddening how much dust will just fall on the mirror between shots.  One of the things I use most is a small LED flashlight.  I can see the dust particles, literally, falling down through the air!  The problem with dust, is, it shows up so readily in your photos, especially in macro photography!  I come armed with a can of air, which helps. Windex, several rags, paper towels, chocolate covered espresso beans... 

Keeping the glass scrupulously clean in between every shot, is crucial but a pain.  I spend much more time cleaning and setting up than actually taking photos.  Before my shot, I'm asking myself "where is the drop going to land?  How do I find this spot each time?  What do I pre focus on?"  Auto focus won't work for these shots, as the drop falls much too fast to focus on, so you have to pre focus where you think the drop will go.   The first drop of milk that falls always does an unimpressive "splat".  That's it. Definitely not exciting.  They look like UFOs to me.  I have many white UFO photos, but I delete them as I go.  Having less photos to upload and delete later, works better for me.

I usually add in a little food color. Consequently, my fingers are blue.  I look like I'm turning into a smurf!  I hope this wears off eventually.  Even my lens cleaning cloth has blue spots now.  Whoops. I like to add color, because white milk doesn't have any contrast.  It's just milk.  Solid white is hard to photograph.  I stay away from photographing white flowers, for the same reason.  The highlights are easy to blow out, if it's all white.  Fun for a night, but now it's back to dropping water tomorrow night...