References like everybody else has said defiantly is a good way to go. Taking photos of your hands in certain poses and then drawing them is great, I sometimes fill a page or two in my sketchbook of hands/arms just to help.
Also building hands up from basic shapes is another good way to do it. The palm being a squared shape, fingers little rectangles, and just continue building from there.
Also building hands up from basic shapes is another good way to do it. The palm being a squared shape, fingers little rectangles, and just continue building from there.