first of all you must know the difference between a normal pony and the princess pony. this one is a princess pony, as you can see it has a long neck, long legs, large wings and a long horn, also it has a kinda squared face.
this one is a normal pony. it has average wings, short fat legs, and a small horn. the male normal head is like the shape of the princess form pony head
these are how the head is seen from different sides and if you are drawing the princess form then see the male side
you can try out many different eyes and many different emotions, and that's the fun part about drawing a pony.
these are some examples of leg poses (front and back).
and now for mane and tail styles and there are some but you can create your own hair styles, of course.
and now to draw, draw one circle and then draw two other stick to each other below the first as shown.
now draw a part of the neck as shown and don't forget the ear and detail it.
now draw the head and the two side legs as you see.
then draw the eye, the other front leg and the torso, also don't forget the mouth and the nose.
now it's time for hair and the other back leg.
now draw the tail, the rest of the neck and the rest of the hair. also notice the Cutie mark; it's like a sea star