You should be more specific fostercreations, however there are a lot of techniques about dresses and how to fit them to the specific body shape of the model, the most common is "conforming". If a dress is made for a specific model it can be dresses with the "conform to" command to the body of the model. But if you change the basic shape of the model you've to od the same with the dress and it could become a big problem. Software that partially solves it are thing (not free) like "the tailor". Another technique is to conform the dress to the body and then create your own morphs or using magnets to let it fits to the body.
Another technique is to pose the dress on the body and then make corrections, this is what you've done applying the same body's pose to the dress. Then you've to correct ti the same way maybe with magnets.
The third way is to use dynamic clothes, available from version 5 and 6 of
Poser, with a special technique (well described in our forums too) the colth will fit to the body automatically, even if corrections are needed in this case too...