Gets a bit easier when you learn the origin and insertion points and because you know the bones you feel like your building something instead of just drawing and guessing at where the muscles end HOWEVER gesture and shape appeal are much more important than 100%accurate anatomy but learn all you can

Imo start with the skeleton and work your way out get the major bones like the sternum, collar bones, scapula, humerus, radius and ulna, lilac crest of the pelvis the femur and fibula and tibia and then just the egg shape for the rib cage and bucket shape for the pelvis then learning the muscles-