bok, I think the best trick is to make sure the species of clown is a natural symbiote with the species of anemone you have. With ocellaris, you're likely to get an almost immediate pairing with H. magnifica or S. gigantea. Unforunately, as you probably know, those species don't ship well and so it's difficult initially to get them to survive. Providing them with excellent water parameters until they become established is key. Once established, they are much hardier and forgiving of less than optimal conditions.