any tips on how to draw hand poses?

[obsidian shale]

I feel like I can only draw the front and back of a hand, but when ever I try to draw different poses it looks weird. EVEN when I use references it looks super stiff, and I'm getting tired of drawing a character just waving with one hand behind their back.

[heavy delta]

I have the same problem. Study and practice. (Also the thumb on the hand facing us is a bit long)

[obsidian shale]

I know! For some reason I ALWAYS make the thumb super long. Still trying to fix that before I move onto other more difficult hand poses.

[meager mulch]

Draw hands from reference

A lot