Could you also post the animations themselves? The sheets are useful to provide specific critique, but animations are hard to give feedback on without seeing the animation itself.
It would also help if you stated what you're going for with each of these. What are they?

Thanks! Are these meant to be water droplets with different things happening to them? I'll post my thoughts with the assumption that they are, but it might be useless if they're not.

1. What is the droplet falling into? Where does it go? The amount of material that splashes away is much less than what the droplet started with, so it looks odd. It's odd that it disappears rapidly instead of dissipating somehow (e.g. each mini-droplet getting smaller as it moves away from the impact). I think having some indication that it affected the surface it's falling into (ripples or a stain) would help, as would letting the deflected mini-droplets have their own motion instead of disappearing suddenly. The large droplet's motion is unnatural, since it seems to slow down before impact. There are a lot of reference photos/videos out there of droplets of various liquids falling on various surfaces, I recommend looking at those frame-by-frame. There are a lot of little things that happen that are easy to miss, but are important in making the motion look good.

2. I like the dissipation effects in this one, but it's weird that the water first dissipates, and then clumps up. What are you going for? Is it meant to be water turning to steam? Why does it shrink, in that case?
Is the lightning-looking bit lightning, or something else? If it's lightning: Lightning tends to grow, forming channels in the air. This means that it'll grow sort of like a tree through the air, it won't change its shape rapidly like yours does. If you google slow motion lightning, you'll find plenty of videos and images that illustrate this.

3. I quite like this one. The only thing I'd change is the timing, I think it would look more natural if it slowed down towards the end, and held on the last frame.

Liquid droplets IRL tend to be spherical. They may have a teardrop shape after separating from a larger body of the liquid, but they become spherical quickly due to surface tension. Things that are very viscuous, like tar, will retain the teardrop shape longer, long enough for it to be visible before the droplet lands, but water, milk, etc become spheres very quickly. Because of that, animating a teardrop shape will always look a little unnatural. If the teardrop shape is important, keep it because it's more interesting than a sphere/circle. However, keep that in mind.

One last note: You're using a white background, and you're alao using white within the droplet, for the highlight. This means you can't just remove all the white to make a transparent background. If these animations are meant to have transparency, I'd make those separate colours instead of making them both white.

2. I think the droplet should instantly expand into a larger puff of steam, and the steam evaporates, instead of turning into tiny droplets and then turning into an undersized steam cloud. Steam is a gas, it takes up more space than water. It doesn't read as steam when your water turns into something smaller (and with a noticeable delay, too - lightning packs a lot of energy, it vaporises things instantly).

3. I see! I think it might still help to slow the motion near the end down, perhaps by adding extra frames, before it finally freeze-frames on the last frame.

I see about the transparency. That's a neat idea. Wouldn't the light blues also let the lines through a little though? If you're going for a drawn-on-lined-paper look, using a blending mode instead of binary transparency seems like a better idea, if your engine allows it.

First off: you're doing effects animation.
That's what you want to look up for reference.
I'll give you props, because fx animation is hard.

Second: I'm just gonna throw down a bunch of places you can go to look at reference. You'll want to go frame by frame when you look at this stuff, or you won't see what you'll need to do in your drawings easily.

Useful sites:
http://flashfx.blogspot.com/
https://www.tumblr.com/tagged/fx-animation
http://efxanimation.tumblr.com/

Lighting especially:
http://flashfx.blogspot.com/2014/09/fx-notes-and-designs-from-various_16.html

Slow motion video is a godsend:
https://www.youtube.com/user/theslowmoguys
water droplets: https://youtu.be/ynk4vJa-VaQ

These sites should just be a starting point, but hopefully you get the idea. Reference is the starting point of solid animation. Nobody knows how everything works without observation, and animation is communicating something happening.

Thanks for the links!

@Jalonso: Not sure if you remember my previous submissions here, but that's basically the context. Just for reference, they're these:
http://pixeljoint.com/pixelart/77806.htm
http://pixeljoint.com/pixelart/83586.htm
http://pixeljoint.com/pixelart/78886.htm

I can also link you to the whole thing in action, if that would clear things up further, but I'd rather not have that link publicly available til it's fully ready to be released, so that would be over PM.