Make sure that all the stones, right down to the front of the arrangement, are placed with their best sides showing. If a stone has an ugly-looking top you should place it so as to give prominence to its side. Even if this means it has to lean at a considerable angle, no one will notice. There should always be more horizontal than vertical stones. If there are "running away" stones there must be "chasing" stones. If there are "leaning" stones, there must be "supporting" stones.