How to improve my hand drawings?

https://imgur.com/a/urfwry0

They feel too stiff and the fingers are too messy I think

These are looking pretty good! 
It might help to practice another way of drawing hands - use curved lines to get the gesture of each finger, and put a tiny dot or circle to represent where each joint is. 
Also, some hands have a bit of a bump where the joints are.

Personally i try to avoid blocks when drawing humans!! Humans are so curvy, so I only use straight lines when I wanna convey like... a harsher energy? Lol. Keep it up u got this!!