Hey there, I have come to give you pointers! First off, it's great that you've been practicing! That's the absolute best way to improve, haha. My biggest pointer is something you've probably read a million times if you've read any art tutorials, but seriously it works: practice drawing from photos, videos, and life. Direct references limit your drawing in pose/creativity, so it seems tedious and annoying a lot of the time, but the understanding of form, anatomy, and motion that you get from it is invaluable. I think doing that will help you out a lot! You're style is cute (love the eyes of the first one, btw) and you should totally roll with it, but getting a grip on realistic anatomy will translate through to your style and make it a lot more convincing/awesome :)
I know that was super vague and generic, so for some more specific points:
1) Internal consistency! What I mean by that is to make sure that when you're drawing, all the body parts and whatnot line up with eahother and are all appropriately formed in relation to one another. That's still kind of confusing sounding, so for a specific example: take a look at drawing number 2. The tail is looking pretty snazzy, but if we imagine the part of the tail that isn't visible, we realize that it wouldn't connect to the butt where the tail /should/ be coming from in a cat (unless it's weirdly bent). Easy to fix: You just need to move the tail down a bit, but really important. It'll make your drawing a lot more convincing if you keep an eye out for little things like that. The poses you have here are pretty simple and symmetrical, but as you draw more complex poses, it'll be VERY important to watch out for things like joints being the same distance down each leg, making sure arms/legs that are partially obscured would still connect to shoulder blades/thighs, etc.
aaaand
2) Poses! It's easy to latch on to one pose/face angle/etc once you've found one that you're good at drawing (I'm guilty of doing this all the time haha), but you should try and spice it up a bit! It'll be frustrating b/c hard poses are, by nature, harder to draw, but it'll help loads in improving. Plus it'll give you more creative freedom, because before you know it you'll be able to draw cats in all sorts of crazy poses that still look like awesome cat drawings! 
I could rant much more but I don't want to bore you. But seriously, keep up the great work! Seeking critique shows me you're really working to improve, which is awesome Let me know if you ever want any more of me ranting, or redlines, tips, critique on a specific piece, etc! <3
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