Body practice things. I spend my time drawing griffons so I need more practice on pony bodies and legs, which never turn out like I want them to.
A thing to note is how if you use basic circles to shape out their bodies, ponies have a larger circle for the hindquarters that overlaps with a smaller circle for the upper torso, whereas it’s the opposite for griffons (large circle for a wider chest and a smaller circle overlapped for the hindquarters).