Great work, really likes how you distributed attention of the viewer by using line weight. The hand you have drawn looks quite great in terms of their anatomy and overlapping. The only suggestion i can give is that the hands you have drawn seems to be drawn are from a direct orthogonal view, which looks quite flat compared to the whole drawing, and draws unnecessary attention. And the positioning (if you try that yourself) just feels a bit awkward. My suggestion would be to just rotate the forearm into a bit more naturally 3d positions so that the hands reveal more of their three dimensionality. If this is something you struggle with, the milleton technique discussed by antonio would give you a headstart with that,