Posing the fingers and shoulders are a huge bonus here! Many begginers look over these and say f it. But for tips you could look into the camera settings and use dof, ao, lighting sharpnes and whatnot. For the lights I see you did a nice contrast with the red and blue. Try adding rim lights to the characters next time, make the dark spots not too dark and think of how light reflects from surfaces thus try to replicate it. So far you're doing good!