what it is and some techniques.

hydrokinesis is the control of water. this can be from making ripples in the water to creating waves that will obey your every command. hydrokinesis like all other kinesis abilities is very hard to learn and will take time to master. here are a few techniques to get you started.
okay so here is the deal with this technique. have a bowl of water or something full of water that you can see through and set it down and wait for it to settle. now get in a comfortable position. fell the water. become one with the water. a way to help you with being one with the water is to imagine that the water is just an extension of your body that you can control just as you can control your arms and legs to move. now visualize yourself controlling the water like it was part of you and will it to swirl around. now try to make it swirl more and more and try to just keep making it swirl faster and faster. do not think that if there is no progress in the beginning  that you should just give up. keep trying and it might also help if you meditate around water and i don't meditate right before the technique because i don't think i need it but if you think it will help you can meditate and hopefully you will get results fast. this technique is a beginner technique and should be pretty easy if you are an advanced hydrokinesis practicer and if you practice this technique long enough you could also do things like form the water in different shapes and make it spin like a whirlpool. if it helps you can even put a toothpick or a cork or something so if it ripples it will move the cork and you can see if you made a lot of progress
this is a very advanced technique and should only be practiced by professionals. first you need to concentrate and close your eyes and imagine water particles in the air condensing and turning into water droplets then it will form into real water if done right and practiced long enough. once you get to the point of actually making the water you can shape it and mold it into whatever you want.
this pretty much wraps up hydrokinesis or at least what i know of it. Hope This Helps!
Good Luck!