Cooking legends Julia Child and Jacques Pepin demonstrate how they poach eggs in this video. Julia in particular shares a trick you might want to adopt: boil the egg for ten seconds before poaching it.
First, prick the large end of the egg to release any air that could cause the egg to crack. Then give it a quick boil. This, Child says helps the egg keep its eggy shape as it poaches, as do the metal egg poachers. Pepin does it the old-fashioned way, with no ten-second boiling.