i mostly got better at drawing hands by just practicing how to draw them a lot!
what i would do is draw a pose or two over and over again (maybe at slightly different angles and stuff) first with reference, and then draw them again without looking at anything to see how much i can draw from my mind, and then go back and forth between the two until i get enough of a “feel” to draw a certain pose decently without relying on reference. i think after a while you kind of develop patterns in the way you draw hands and from there it becomes easier to draw different hand poses and stuff from scratch
to make the hands you draw look less awkward/stiff, i think it helps to focus more on the overall flow of the composition and silhouette of the hand rather than getting all the details in and anatomy right and stuff in the initial stages
when drawing hands in perspective i think it helps to visualize them as 3d shapes
to get the foreshortening right (aside from using perspective guides and whatnot) i like to just draw the hand first, and then eyeball the perspective and adjust its size and position until it looks right
(select with lasso tool > ctrl+t to transform +right click for more transform options)
another thing i do is take reference pictures with my ipod (any camera works tbh. i just find using a mobile device to be more convenient)
by holding the camera close to my hand i can get a really exaggerated perspective like this:
it’s nice because i can get the ref for the exact pose and angle i’m looking for without having to do a lot of internet fishing