A good drawing is the most important foundation for a great work of art. In order to draw horses well, you really need to understand how they are built and you need to know the names of various parts of the horse.
Click to Enlarge Image taken from the book ""Draw Horses with Sam Savitt"
Next, you will find it very helpful to begin to draw parts of the horse with the help of a grid. Take your time and learn to draw each feature well, before you move on to the entire horse.
Image taken from the book ""Draw Horses with Sam Savitt"